Indulge in the flavors of traditional lasagna without the pasta! This low carb Spaghetti Squash Lasagna Casserole recipe is gluten-free, quick and easy to prepare, and delightfully low in carbs. It’s a healthier twist on a classic favorite that’s sure to become a weeknight staple.
A longtime reader favorite, this Spaghetti Squash Lasagna recipe will turn you into a believer of all things Spaghetti Squash. It’s one of the earliest Confessions recipes from the baby blog days, and yet it’s one I revist time and time again.
While I love a good pasta dinner with actual pasta, I wholeheartedly do not miss the noodles in this lasagna dish. It one hundred percent rivals my favorite pasta dishes, as it’s full of the good stuff – flavorful Italian chicken sausage, creamy ricotta cheese, and toasty mozzarella. Just instead of using lasagna noodles, we are using cooked spaghetti squash!
It’s a great comfort food recipe to warm you up on a chilly day while also getting in your daily veggies!
Love low carb lasagnas? Check out this noodle-less Zucchini Lasagna Recipe!
Why You Will Love this Recipe
- Enjoy all the flavors and cheesy goodness of traditional lasagna without the heavy carbs
- Huge, filling portion to keep you full and satisfied
- Filled with protein, fiber, and healthy fat – making it macro friendly, Keto friendly, and 21 Day Fix/WW friendly
- This easy weeknight meal is perfect for Meal Prep because it tastes even better leftover
- You can customize the fillings to your liking, adding additional veggies and swapping in your favorite protein
Ingredients
For full ingredients and amounts, be sure to check the recipe card below!
Here’s what you need to make this delicious, noodle-less lasagna:
Olive oil cooking spray – you can sub olive oil, but I love using my EVO to cut down on the amount of oil
Spicy Italian Chicken Sausage or Turkey Sausage – I make my own chicken sausage using ground chicken, but you can also use store-bought
Onion – yellow or white onion works best
Garlic – I love fresh garlic in this, but you can swap garlic powder if that is all you have
Part skim ricotta cheese – cottage cheese also works great
Egg – this will help as a binger for the ricotta mixture, but you can omit if you have an egg allergy
Homemade tomato sauce – or a no sugar added jarred marinara sauce like Rao’s
Cooked spaghetti squash – you want a medium sized squash that will yield about 4 cups cooked
Mozzarella cheese – freshly shredded is best
Parmesan cheese – for a flavor punch
Fresh basil – swap in 1/2 tsp dried if you don’t have fresh
Salt and pepper – important for seasoning the squash and the ricotta cheese
How to Make Spaghetti Squash Lasagna
You can find step-by-step instructions in the printable recipe card below.
Step One: Prepare the Spaghetti Squash
- This recipe calls for cooked spaghetti squash, so the first thing you need to do is prep your squash one of several ways: in the oven, in the microwave, in your Instant Pot, or in the Slow Cooker. I have a whole post on how to prep spaghetti squash for help!
- Once your squash has cooked and cooled, discard the seeds and use a fork to remove the “spaghetti” strands of squash. To remove excess moisture from the squash noodles, wrap them in a clean kitchen towel or paper towels and give it a squeeze over your sink or a large bowl.
- Season the cooked squash noodles with a sprinkle of salt and pepper.
Step Two: Prepare the Filling
- Spray a large skillet or cast iron pan with olive oil cooking spray. Saute onion over medium heat until translucent and aromatic. Add sausage and brown until cooked through. Finally, add minced garlic to the pan and cook for an additional minute. Remove from meat and veggie mixture from heat
- To make the ricotta mixture, place ricotta in a medium sized bowl. Stir an egg, parmesan cheese, and a sprinkle of pepper.
Step Three: Assemble the Lasagna
- Preheat your oven to 350°F, then begin the layering process. First, spoon about half of your sauce on the bottom of the casserole dish.
- Next, add the cooked sausage. Layer spaghetti squash over the sausage then add the rest of the sauce and some fresh chopped basil.
- Finally, top sauce with the ricotta cheese mixture and then add the shredded mozzarella.
Step Four: Bake
- Bake until cheese is melty and bubbly – about 15-20 mins. To brown the cheese, broil on low for 5-10 minutes at the end, but watch carefully. It sneaks up on you!
- Remove from oven and let sit for a few minutes. If there is excess water at the bottom of your pan, you can carefully try to drain it out from the corner of the pan or serve with a slotted spoon.
- Garnish with fresh basil before serving!
Substitutions + Variations
This recipe is fully customizable to your family’s preferences…and to what you have on hand!
- Swap the chicken sausage for lean ground beef or ground chicken. You can even use leftover meat sauce.
- Sub protein packed cottage cheese for ricotta. For a dairy free version, swap in vegan ricotta.
- Omit the meat entirely for a vegetarian lasagna. Add in additional veggies such as sautéed spinach and mushrooms.
- In a pinch, sub a can of crushed tomatoes and Italian seasoning for the tomato sauce.
- Make lasagna boats instead of a casserole, and layer your cheese, tomatoes, and sausage inside each half of the cooked spaghetti squash.
Recipe FAQs
Yes! I love this recipe for meal prep and you can do this several ways. You can assemble the lasagna ahead of time, but don’t bake. Refrigerate it for up to 24 hours before baking. Or you can ingredient prep – ie prepare the tomato sauce, squash and meat/veggie mixture up to three days in advance. Then all you have to do is assemble and bake the lasagna the day you want to eat it.
Yes! While most winter squash are higher in carbohydrates, Spaghetti Squash is lower in carbohydrates. In one cup of cooked spaghetti squash, you’ll find 10 grams of total carbs. For more spaghetti squash nutrition info, check out this post.
Yes! Spaghetti Squash freezes exceptionally well! If you know you would like to freeze this spaghetti squash lasagna, removing as much liquid before and after baking will ensure that your squash will taste great after thawing and reheating. For more information, check out the Meal Prep and Storage section below.
This is such a hearty meal with a huge portion, so I prefer to enjoy it with a small side salad. My kids will eat their piece with homemade garlic toast.
Meal Prep and Storage
To Prep Ahead:
- This Spaghetti Squash Lasagna is an excellent candidate for meal prep. You can assemble it up to 24 hours before baking. Just follow the recipe instructions up to the point of baking, then cover the baking dish with foil and refrigerate. When you’re ready to enjoy it, simply bake as directed.
- Another option is to prep the tomato sauce, squash and meat/veggie mixture up to three days in advance. Then all you have to do is assemble and bake the lasagna the day you want to eat it.
To Store:
- If you have leftovers or want to store a fully cooked lasagna, allow it to cool to room temperature. Store any remaining lasagna in an airtight container in the refrigerator for up to 3-4 days.
To Freeze:
- To freeze Spaghetti Squash Lasagna, wrap individual portions or the entire dish tightly with plastic wrap or aluminum foil. Place the wrapped lasagna in an airtight container or a resealable freezer bag to prevent freezer burn. Frozen lasagna can be stored for 2-3 months.
To Reheat:
- Reheat in a preheated oven at 350°F until the lasagna is heated through, typically about 15-20 minutes for individual portions or 30-40 minutes for the entire dish.
- Alternatively, you can microwave individual servings on a microwave-safe plate for 2-4 minutes or until hot.
- To reheat frozen lasagna, it’s best to thaw it in the refrigerator overnight and then follow the reheating instructions above.
More Healthy Spaghetti Squash Recipes
Mediterranean Stuffed Spaghetti Squash Boats
Shrimp Scampi with Spaghetti Squash
Simple Spaghetti Squash with Meat Sauce
Spaghetti Squash Chicken Alfredo | What Molly Made
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Spaghetti Squash Lasagna
Ingredients
- Olive oil cooking spray [I use my EVO]
- 1 lb spicy Italian turkey sausage casings removed
- 1/4 onion diced
- 2 cloves garlic minced
- 1 1/4 cup ricotta cheese WW can use fat free
- 1 egg
- 1 1/2 cups homemade tomato sauce or a no sugar added jarred sauce like Rao’s
- 1 cooked spaghetti squash about 4 cups of squash
- 2/3 cup mozzarella cheese
- 1 tablespoon parmesan cheese
- Fresh basil
- Salt and pepper
Instructions
- Spray a pan with olive oil cooking spray, saute onion until soft. Add turkey sausage and brown until cooked through. Add garlic and cook for an additional minute. Remove from heat.
- Discard seeds from the squash and use a fork to remove your “spaghetti.” To remove excess moisture from the squash, place it in a clean kitchen towel and give it a squeeze. Then season the squash with a little salt and pepper.
- Stir an egg, parmesan cheese, and a sprinkle of pepper into the ricotta.
- Preheat your oven to 375 degrees F. Spray a casserole dish with a olive oil cooking spray and begin the layering process.
- First, spoon about half of your sauce on the bottom of the casserole dish.
- Next, add the cooked sausage. Layer spaghetti squash over the sausage then add the rest of the sauce and some fresh chopped basil.
- Finally, top sauce with the ricotta cheese mixture and then add the shredded mozzarella.
- Bake until cheese is melty and bubbly – about 15-20 mins. To brown the cheese, broil on low for 5-10 minutes at the end, but watch carefully. It sneaks up on you!
- Remove from oven and let sit for a few minutes. If there is excess water at the bottom of your pan, you can carefully try to drain it out from the corner of the pan or serve with a slotted spoon.
- Garnish with fresh basil before serving!
Notes
- This Spaghetti Squash Lasagna is an excellent candidate for meal prep. You can assemble it up to 24 hours before baking. Just follow the recipe instructions up to the point of baking, then cover the baking dish with foil and refrigerate. When you’re ready to enjoy it, simply bake as directed.
- Another option is to prep the tomato sauce, squash and meat/veggie mixture up to three days in advance. Then all you have to do is assemble and bake the lasagna the day you want to eat it.
- If you have leftovers or want to store a fully cooked lasagna, allow it to cool to room temperature. Store any remaining lasagna in an airtight container in the refrigerator for up to 3-4 days.
- To freeze Spaghetti Squash Lasagna, wrap individual portions or the entire dish tightly with plastic wrap or aluminum foil. Place the wrapped lasagna in an airtight container or a resealable freezer bag to prevent freezer burn. Frozen lasagna can be stored for 2-3 months.
- Reheat in a preheated oven at 350°F until the lasagna is heated through, typically about 15-20 minutes for individual portions or 30-40 minutes for the entire dish.
- Alternatively, you can microwave individual servings on a microwave-safe plate for 2-4 minutes or until hot.
- To reheat frozen lasagna, it’s best to thaw it in the refrigerator overnight and then follow the reheating instructions above.
Bianca says
Hi there! If I omit the meat and add extra veggies instead, what would be the cups count? Thanks so much!
Nancylynn says
The containers? If you omit the meat it will be 1/2 RED, and the GREEN will depend on how many extra veggies you intend to use. You should count an extra 1/4 GREEN per every 1 cup of veggies total that you add to the recipe. I hope that makes sense!
Andrea says
I DEFINITELY modified by swapping out the spaghetti squash for whole wheat spaghetti, but it still tasted delicious! I went to cook my squash tonight only to discover that my grocery delivery sent canary melon instead… oops! I had a pound of pasta on hand, so we improvised! I’m excited to follow the recipe as-is next time!
Nancylynn says
Oops – gotta love grocery delivery swaps! lol! Great improvising and I can’t wait for you to try it when you have a real spaghetti squash!
Katy Bursch says
This was so delicious (like all of your other recipes!) Rather than use a clean towel to wring out the spaghetti squash, I threw it in the salad spinner for a few good pumps. It took out a ton of liquid and I didn’t have any trouble with a runny dish. I also didn’t have to worry about burning my hands. For anyone that has a salad spinner, give it a try! The kids love using it, too, so any easy way for them to help.
I have been following your weekly meal plans since January first and I am SO glad I stumbled upon you! You make my health journey with three littles underfoot so much easier than it could be. Thank you so much!!
Nancylynn says
So glad you are here!! Have you used the full plans? Those make it even easier!
P.S. Whoa, mind blown on the salad spinner trick! Thank you for sharing!
Taylor says
How is this recipe only 1/2 blue for one serving? The ricotta plus the mozzarella comes out to almost 2 full cups, which makes one serving almost 1/2 cup of cheese. I believe a blue container is only 1/3 cup, so I’m not sure how it’s only counting as 1/2 of that? Are you counting the ricotta as something other than blue?
Nancylynn says
Yes, ricotta is a RED on the 21 Day Fix.
Lisa says
I made this yesterday and baked it today. It was perfect. Only issue is the serving size is too big. I cut it down to 1/6 of the pan and that was still huge. I don’t love ground turkey so I will make it again with ground beef. I adjusted my counts to 1 red ( rounded up), 1/3 blue and 1 green. Does that sound right for 1/6?
Nancylynn says
That sounds right! Glad you liked it!
Deb says
First 21-Day Fix Recipe of yours that I’ve baked, and it certainly won’t be the last! This recipe is absolutely amazing, exactly as written! (Actually, I didn’t have ground turkey on hand, only ground beef, but that was my only deviation.)
Nancylynn says
Yay! Perfect!
Shauna says
Thank you for this recipe! This is one of the best things i’ve ever made when trying to eat healthier, as part of the 21 day fix or not. It feels so decadent and filling, even though it’s relatively low-cal and fits comfortably in the limits of the 21 day fix containers. Seriously thank you from the bottom of my very pleased stomach!
Christina R. says
I stumbled upon your site once I finally got my husband back on 21 Day Fix with me, after a 2 year “break” for me. My husband is a foodie. I am overwhelmed by food prep. Your plan made things so easy, and Oh. My. God. Are the chili, and lasagna AMAZING!!!! I have done 21 Day Fix with pretty simple meals each of the rounds I have done on-and-off over the last 5 years. These meals are so gourmet, and my husband is actually enjoying 21 Day Fix for the first time, and I think he’s going to keep on the plan for an extended period from this point forward! I can’t wait to try all of your other recipes!!! Thank you so much!!!!
Nancylynn says
You honestly made my day, Christina! This is my whole goal – to make eating healthy doable, sustainable, and enjoyable!!! Thank you for taking the time to write such a wonderful comment!! Excited to hear about your progress on this plan!
Bella Hardy says
Hey, Nancylynn, just wanted you to know that I tried the spaghetti squash lasagna, and it was a great success. I will admit, however, I tweaked your recipe a bit.
Nancylynn says
Well that’s great!! I would love to hear how you tweaked it!!
Britni says
Love this recipe! Especially for our gluten free family!! Quick question, have you or anyone tried making ahead and freezing? Does it turn out ok? Thanks!
Nancylynn says
I have not tried this, but I am curious to see if someone else has!
Shanna says
I have made this and divided up into single portions, then froze. I let it thaw completely overnight and heated for lunch the next day. AMAZING!
Nancylynn says
Great feedback! Thank you Shanna!
Christina says
So Good! Was a little liquidy, but probably because I used cottage cheese instead of ricotta, and we didn’t mind. I also used half spaghetti squash, half riced cauliflower.
Nancylynn says
I love the idea of adding riced cauliflower!! Thanks, Christina!
Emily says
I just found this recipe on Pinterest and made it tonight. It’s amazing! My husband and three year daughter loved it, too. I used the 21 Day Fix sauce recipe and it turned out great. The tip about ringing the squash in a dishcloth was super helpful as well. I seriously haven’t loved a new recipe this much in a long time! Thank you so much and keep up the great work!
Nancylynn says
YAY!! I need to redo these pics, but thank you for making it despite the not so pretty photography! And I am so happy it was a hit with the whole fam…that’s the BEST.
Beth says
According to your written directions, the order for layering this lasagna is:
Sauce
Sausage
Spaghetti squash
Sauce
Ricotta mixture
Mozzarella
It seemed weird to have all the cheese at the top, but that’s what I did, against my better judgment. After I was finished, I noticed that this didn’t match up with your photos below the directions at all! Wish I would have seen the photos first, but that’s my whole fault for not being thorough, I guess. 🙂
But aside from the weird layering issue, the flavor is really good when I mix it all together! Will definitely try this again!
Nancylynn says
Hey – so after making this again different ways, we decided we liked the cheese best on top, so I changed the directions. Maybe what I will do in the future is give two options? Thanks for your feedback!!
Beth says
Ohhhh okay! Thanks for the explanation! I thought maybe I was going crazy. 😉 But regardless of the order of the layers, it was so tasty and I’m looking forward to leftovers tomorrow!
Nancylynn says
No problem – you bring up and great point and I think other people may have had the same confusion! Glad you still enjoyed it!
Rachael says
I am still confused, in what order did you do the layers in the pictures?
Nancylynn says
Potatoes at the bottom, the the trivet, then carrots and the meatloaf on top.
Lacey says
Made this tonight and it’s awesome! Did what you said and soaked up excess water from the squash and it came out great! Used the left overs for meal prep for the week! Thanks!
Nancylynn says
YAY!!!!!!!!!!!!!
Kass says
Hey just made this tonight I used a 9×13 pan what would be my portion ?
Nancylynn says
It sounds crazy, I know, but a serving is 1/4 of the recipe…so divide your pan into 4 equal parts! YUM!
Jackie Johnson says
This was delicious with ground beef for my bland taste buds. The full bowl while doing the Fix is a great thing.
Nancylynn says
We love it with beef, too!!! SO happy you enjoyed it!!!
Ashley Henry says
I might be blind, but where’s the recipe for the homemade sauce? I would like to try this this week! Thank you
Nancylynn says
Not blind! The hyperlink seems to be missing, so here you go! https://confessionsofafitfoodie.com/2015/03/21-day-fix-homemade-tomato-sauce/
Cody says
Hi there, I’m still a little confused on the containers. If it’s homemade sauce with no sugar, is the squash and the sauce adding up to 1 green per serving or would it be 2 greens then?
Nancylynn says
Hi! It’s 1 1/4 green per serving…the sauce and the squash added together, yes 🙂
Sarah McGehee says
i never saw where to add the onion to the recipe….did i miss it?
Sarah McGehee says
ahhh…nevermind saw it before the sausage….sorry!!!!
Arielle Clark says
Hi
Would this recipe work with ground turkey?
Nancylynn says
It sure would! Season it up with some Italian seasoning and garlic powder – yum!
Brooke says
I tried this last night and absolutely LOVED IT! I used about 2 cups of my homemade marinara sauce (I am a huge fan of everything SAUCE), and I used some extra cheese, too. OH and I used ground beef instead of sausage. My spaghetti squash also likely yielded more than 4 cups of squash – I will definitely have 6-8 servings in my pan (I measure each serving about 1 1/4 green container or so).
IT IS SO DELICIOUS. (I even forgot to squeeze the water out of the squash before baking and it still turned out great). I think it’d be hard to go wrong with this recipe!! 😀 Thank you!
Nancylynn says
Thank you SO much, Brooke!! I also LOVE this with ground beef and so does my hubby!! Happy you have some extra for leftovers this week, too – that’s always the best. Thanks for making my night!!
Laura says
Tried this last night and it is great!!
Nancylynn says
Yay!!! SO happy to hear!!
Jess says
I noticed you have how many containers it counts for but what’s the serving size? How much do you eat to account for the containers listed above?
Thank you
Nancylynn says
It’s 1/4 of your pan! It’s huge!
Amber says
This sounds great but I’m not a sausage fan. What do you think about ground chicken or beef instead? Thanks so much!!
Nancylynn says
Either would be wonderful! Just season the meat with some Italian Seasonings and garlic powder. YUM!
Katie says
Hi
So I made this last night and WOW is it ever good! The spaghetti squash I found were so small, so I got two and that was perfect. My husband and I both are on the 21 day fix diet. We are thrilled to have found this recipe and your site! Thank you so much. Oh and mine was not to runny, it was perfect!
Nancylynn says
Thank you so much for the wonderful message! So glad the recipe worked out! Happy holidays to you!
Molly says
When using jarred sauce, what would total colors/number of containers be?
Nancylynn says
Does your jarred sauce have added sugar? If not, it’s still a green!
Molly says
Yes. It has like 6 grams…I didn’t realize it or else I would have probably used something else. 🙁
Molly says
So, what colors would I have used?
Nancylynn says
1 1/2 RED, 1/2 BLUE, 1 GREEN 1/4 PURPLE per serving
Nancylynn says
1 1/2 RED, 1/2 BLUE, 1 GREEN. 1/3 PURPLE per serving
Molly says
If you use a jar of container for the sauce and count it as a purple, then what is the container colors used for 1/4 size? Is it still 1 green, 1.5 red, .5 blue, and the 1 purple?
Amanda says
I used a 9×9 pan by mistake. 1/4 of this for one serving seems insane!!!!!
Nancylynn says
Yup – that’s one of the reasons I love this meal so much! Enjoy :).
Courtney Samples says
What size casserole dish do you use to make 4 servings? Does it make a difference (probably a naive question haha!)?
Nancylynn says
Hi! Not at all – that’s a good question! I use an 8×8 pan and divide it into 4 squares.
Michelle says
Do you know the calorie count in this dish? It was delicious btw- my whole family loved it!
Nancylynn says
Hi! I actually don’t count calories, so no…but I have been getting a lot of requests for this. Maybe I will have to add this info in the future! Try loading it into my fitness pal. So happy it was a hit!!
Nancy says
Hi,
I made this last night and found so much liquid in the bottom of the pan. I also had a very hard time figuring out some of the directions or lack of them. Everyone really liked it but those were my issues with this dish.
Nancylynn says
Hi Nancy – thank you for your feedback! I will take a look at the directions to see how to improve them for other readers. Also, you can use cheese cloth or a clean kitchen towel to remove some of the liquid from the squash. Hope that helps!! Thanks!!
Gina says
Can this recipe be made ahead of time? (ie – the day before or can it be frozen?) Thank you
Nancylynn says
I haven’t tried to freeze it, but it reheats very well! You can also prep it, keep it in the fridge, and then bake it when you are ready!
Gina says
Great! Thank you.
Brittany says
How do you count containers after its cooked ? Like when you are serving it?
Nancylynn says
Divide into 4 equal servings – 1 1/4 RED 1 GREEN 1/2 BLUE
Kelli says
Would love to know how to cook spaghetti squash for this recipe. I have never cooked this before.
Nancylynn says
Hi Kelli!! Here’s how I make my squash – 1. Using a sharp knife, cut slits all over the squash. 2. Microwave for 10-20 mins- checking periodically. When it’s done, it will feel like a ripe avocado. 3. Let it cool. Then slice it in half and remove the seeds. 4. Finally, use a fork to shred it and make spaghetti!
Kelli says
Where do you buy the sausage? i could not find it so i bought regular turkey breakfast sausage. i plan to sprinkle Italian seasonings on it.
Nancylynn says
Hi! Hmmm…I can usually find the sausage in any grocery store. My favorite is from The Fresh Market, but don’t get to go there much. I would add italian seasoning and maybe some crushed red pepper! Also- this is written for 4 servings, so divide it into 4 portions for the container count!! Hope this helps!!
pepepr says
Is the sauce a purple or green? I see where they are either.
Nancylynn says
Homemade sauce is a GREEN because it doesn’t have added sugar. If you buy a jar of sauce, it counts as a PURPLE. My sauce is my grandmother’s recipe – so easy and inexpensive! Try it!
Korina says
If you buy a jar of sauce, but it has no sugar added would it then still count as a green?
Nancylynn says
Yes!
Alyssa says
Am i missing where your homemade sauce recipe is located???
Nancylynn says
I’m sorry – I think there is a problem with my links – but this should work! https://confessionsofafitfoodie.com/2015/03/21-day-fix-homemade-tomato-sauce/