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This creamy, cheesy Spaghetti Squash Casserole is a comforting dinner everyone will love. Tender spaghetti squash is baked in a zesty tomato cream sauce with spicy sausage for bold, savory flavors. It’s naturally gluten free and perfect for a cozy meal any night of the week!
Delicious Details
- Cuisine Inspiration: Italian-inspired
- Primary Cooking Method: Stovetop, Oven
- Dietary Info: Gluten-free, Low Carb
- Skill Level: Easy
Why You’ll Love This Spaghetti Squash Casserole Recipe
This spaghetti squash casserole is one of our favorite weeknight comfort foods. I’ve been making it for years and it’s one of the best ways I have to get my kids to eat spaghetti squash instead of their beloved pasta. I also shared it with the first person I met who was gluten free besides me, and I know it’s been a staple in her family since 2012 (you can see her comment below).
It’s 100% gluten-free, yet just as creamy, cheesy, and delicious as any pasta casserole recipe. It’s easy to make with a rich tomato cream sauce that’s filled with spicy sausage for the perfect amount of kick. Baked with tender spaghetti squash underneath melted cheese, this is a hearty and satisfying casserole that’s sure to win over everyone, even pasta lovers!
- Flavorful. The flavors in this casserole are light and fresh, but warming. The sauce is filled with the delicious flavors of zesty tomatoes, a touch of wine, and spicy sausage that bulks it up just enough to make this recipe into easy weeknight comfort food.
- Veggie-packed. If you’re avoiding gluten, you might already know spaghetti squash is a great alternative to pasta. It’s also a great way to bring veggie power to a casserole! This winter veggie is a delicious replacement for noodles in this recipe, and just as hearty.
- Beginner-friendly. Just getting acquainted with spaghetti squash? This spaghetti squash casserole is PERFECT. It doesn’t call for any fancy preparation or complicated ingredients.
- Versatile. There are so many ways to adapt this recipe! Add extra veggies or change up the sauce and seasonings. And of course, if you’d prefer to bake pasta instead, you can always substitute the squash with your favorite noodles.
Wow. Just yum. I have made a lot of spaghetti squash recipes. Some are good. Some are really not. This is by far my favorite spaghetti squash dish ever. This is probably up there with one of my favorite dishes ever, period. -Angel
Oh such a delicious dish. Thanks so much. This will be on our monthly meal planner. 😋 -Melanie
Ingredients You’ll Need
This baked spaghetti squash casserole recipe is super straightforward! Here are my notes on what you’ll need to make it. Scroll down to the recipe card for a printable ingredients list.
- Spaghetti squash – This is a common winter squash that you’ll find in the grocery store alongside other types like acorn squash, butternut squash, etc. See below for details.
- Sausage links – I like to use raw hot turkey sausage to keep the sauce leaner while adding a nice bit of heat. Feel free to use pork sausage, Italian sausage, or another kind, spicy or mild. Make sure you purchase a brand that is gluten free, if needed.
- Onion – Good options are yellow onion, white onion, or shallots.
- Red wine – Choose a dry red, like Cabernet Sauvignon or Merlot. If you’d prefer to cook without alcohol, you can omit the wine, replace it with stock, or add a splash of balsamic vinegar.
- Canned crushed tomatoes – My favorite brand is Tuttorosso. Their crushed tomatoes come with basil included. If you use another brand, you may want to sprinkle a little fresh or dried basil into the sauce instead.
- Herbs and seasonings – Dried oregano, salt, and pepper. You can also use Italian seasoning instead of oregano if you’d like. I also like to bring some fresh or dried parsley into the mix.
- Heavy cream – You can substitute milk for heavy cream, but the sauce won’t be quite as rich. Plain Greek yogurt or sour cream are also good choices.
- Grated parmesan cheese – I love the salty sharpness that freshly grated parmesan (or pecorino) brings to the sauce. Save some of the cheese to sprinkle over top when serving.
- Frozen peas – Optional, but they give the casserole some color and extra texture.
- Shredded mozzarella cheese – Because no casserole is complete unless it’s baked under melted cheese. You can use fresh mozzarella, or another kind of cheese, like cheddar.
What is spaghetti squash?
Most spaghetti squash you find in stores is oval-shaped and pale yellow. It’s different from other types, like butternut squash, in that its insides are tender and stringy. When cooked, this stringy flesh can be shredded into long “noodles” with a neutral flavor that blends well with just about any ingredient you mix it with. As soon as I started treating these “noodles” much like traditional spaghetti, it opened a world of delicious recipes (this spaghetti squash casserole included!).
How to Make Spaghetti Squash Casserole
Every casserole starts with a great baking dish, and for this recipe, I recommend a glass or ceramic casserole dish. I like to use the 1 ½-quart oval French White Corningware from this 12-piece set. Once your ingredients are assembled, follow these steps! Scroll to the recipe card for printable instructions.
- Cook the squash. First, you’ll need to cook the spaghetti squash using your preferred method. Check out my post on how to cook spaghetti squash for 5 easy ways to cook it, from the oven to the slow cooker. Afterward, scrape out the flesh with a fork to make long “noodles”.
- Saute the meat and onions. Next, brown the sausage in a pan. Add the onion, and cook until it’s soft and translucent.
- Make the sauce. Stir in the wine, a can of crushed tomatoes, and the seasonings. Let it simmer a bit before stirring in heavy cream, parmesan cheese, and frozen peas.
- Combine. Pour the sauce over your spaghetti squash. If there’s too much sauce, just save the extra to pour over later or use for another meal (it’s delicious over gluten-free gnocchi!)
- Bake. Transfer the saucy squash noodles to a baking dish and top with mozzarella cheese and parmesan cheese. Bake the casserole at 400ºF for 10-15 minutes until hot, melty, and golden.
Casserole Tips and Variations
Looking to make the most of this cheesy spaghetti squash casserole recipe? Follow the tips below. I’ve also included some easy ways to change up this recipe, and I’d love to hear your ideas in the comments.
- Meal prep this recipe. The spaghetti squash for this casserole can be cooked and stored airtight in the fridge for up to 3 days in advance.
- Skip the cheese or add more. The layer of melty mozzarella gives this recipe its signature bubbly casserole top, but if you’d prefer to skip it, go right ahead. You could also make it even more gooey with extra cheese if you prefer.
- Replace the sausage. Instead of spicy sausage, fill this casserole with diced chicken or ground beef instead.
- Vegetarian. For a vegetarian spaghetti squash casserole, substitute the sausage with your favorite cooked vegetables. Try broccoli, cauliflower, diced bell peppers, green beans, sweet corn, or a combination of veggies. You can also replace the meat sauce with marinara sauce.
- Different sauce. Play around with different pasta sauces. This gluten-free casserole would taste amazing with a base of homemade vodka sauce, bolognese sauce, or even creamy alfredo sauce for something different.
Storing and Reheating Leftovers
- Refrigerate. Store any leftover spaghetti squash casserole in an airtight container in the refrigerator for up to 4 days.
- Reheat. Warm the casserole under foil in the oven at 350ºF until it’s hot throughout. You can also reheat portions in the microwave or in a covered skillet on the stove.
- Freeze. You can freeze spaghetti squash casserole, keeping in mind that spaghetti squash tends to get a little watery when it’s thawed. Let the baked casserole cool completely to room temperature. Wrap leftovers in a layer of plastic wrap and then foil, and keep them frozen for up to 3 months. Defrost the casserole in the fridge overnight before reheating.
Make It a Meal
This spaghetti squash casserole is a meal on its own, or you can serve it with easy sides.
- Add a salad. We love this Italian wedge salad or you can serve it alongside a hearty Italian Chopped Salad.
- Serve with more veggies. It’s perfect to pair with juicy garlic roasted mushrooms or tender Parmesan Roasted Brussels Sprouts.
- Don’t forget the bread. If you aren’t low carb, then you can’t resist a basket of fluffy homemade gluten free garlic knots. Or, try these gluten free soft breadsticks that make you feel like you’re sitting down to dinner at the Olive Garden!
Baked Spaghetti Squash Casserole
Ingredients
- 1 spaghetti squash
- 3 raw turkey sausage links hot or mild, or you can use pork sausage
- 1/2 large sweet onion, chopped
- 1/4 cup red wine
- 15 oz crushed tomatoes (I typically use Tuttorosso when I am using crushed tomatoes. It has a little basil in it, so if you use a brand without basil, you may want to add a little fresh or dried)
- 1/2 teaspoon dried oregano
- 1/2 teaspoon kosher salt
- freshly ground pepper
- 1/4 cup heavy cream
- 1/4 cup grated parmesan cheese
- 1 Tablespoon fresh parsley or 1 teaspoon dried parsley
- 1/2 cup frozen peas optional
- 1/4 cup shredded mozzarella cheese
- 3 Tablespoons grated parmesan cheese for topping
Instructions
- Cook the spaghetti squash in your desired manner (see link in Notes for five methods) and scrape out the "noodles". Preheat or keep your oven set at 400ºF.
- Heat a pan over medium heat.
- Squeeze the sausage out of the casings into the pan, and cook until is cooked through and browned.
- Add the onions and saute until translucent and soft.
- Add the wine, tomatoes, oregano, salt, and pepper, and simmer until it is hot and the onions are fully cooked.
- Stir in the heavy cream, parsley, ¼ cup parmesan cheese, and frozen peas.
- Pour enough sauce over the squash noodles until it is as saucy as you like (there may be some extra sauce, which you can serve on the side).
- Pour the mixture into a 1 1/2-2 quart glass or ceramic baking pan or casserole dish that has been sprayed with olive oil or cooking spray.
- Sprinkle the mozzarella cheese evenly across the top of the casserole.
- Bake for about 10-15 minutes, or until hot and bubbly, and the cheese is golden brown.
Notes
- See how to make spaghetti squash in your oven, microwave, slow cooker, Instant Pot, or grill.
Did you make this?
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Oh such a delicious dish. Thanks so much. This will be on our monthly meal planner. 😋
So happy to hear this!
Wow. Just yum. I have made a lot of spaghetti squash recipes. Some are good. Some are really not. This is by far my favorite spaghetti squash dish ever. This is probably up there with one of my favorite dishes ever, period. Soooooo goooood
Thank you so much! Yes, I have loved this dish for many years.
I made the Baked Spaghetti Squash Recipe with Spicy Sausage Tomato Cream Sauce. Your recipe is perfect, except I poured in most of the sauce. It was our first spaghetti squash recipe and we loved it! Thanks much!
I’m so happy to hear that you enjoyed the recipe, Nan, and thank you for rating it. 🙂
Is the mozzarella cheese supposed to be cooked in the sauce or on top? I didn’t see that in your directions.
I’m so sorry for the delay in our response. The mozzarella cheese is placed on top of the casserole before it gets baked in the oven.
This recipe looks enticing and delicious. In September, I will be publishing a recipe round up featuring baked spaghetti, and I was wondering if I can include your baked spaghetti squash recipe in my round up and use one of your pictures. I will link back to your site for the recipe. Thanks for your consideration.
Outstanding your recipe is amazing
Hi my friend, love all your recipes, I just noticed the way you made this sauce, you put onions after cooking the meat, that’s how I make my pasta sauce, I put lots of onions and 2 cloves of garlic. It seems like if you brown the onions slightly to bring out the sugar in the onion, it will sweeten the sauce naturally, and give a nice flavor. I learned that from a woman who was from Italy and my dad who ‘s a baker and can cook like a little ole Italian lady. If you like onions that is, but I think onions or garlic should go in the sauce after the meats are cooked, just like you did here, but I notice you didn’t do that for your lasagna sauce. I’m sure with all those flavors it wasn’t even noticed, but I was just curious. I ‘m gonna try this recipe, it’s almost like a vodka sauce, without the vodka, just the cream, plus I love peas. Sounds yummy, can’t wait to try, my son has been on this low carb. way to eat, so this will work out great. Oh yeah, just wanna say, I use the Barilla, no cook noodles too, their so much thinner and taste like fresh noodles. I even put a small amount of cream cheese in my cheese mixture a few times, I love spinach mixed in too. Thanks. Keep on cooking!
Love this recipe, Brianne. Such a delicious option to spaghetti, with the added bonus of being gluten free for those who need it!
Thanks Ann! I love spaghetti squash, almost more than the gluten-free pastas.
Oh, this looks fantastic – that sauce look so tasty and a great choice to put it over spaghetti sauce!
Thanks! I have only just started trying the gluten-free pasta, so I was just making spaghetti squash for awhile. Great way to get in some extra veggies. But I am sure the sauce would be good over any type of pasta.
I am going to try this tonight. Will let you know how it turns out. About how many people do you think it will feed?
So glad you are giving it a try. It depends on the size of the spaghetti squash you get, but I would say it would feed 4.
I made it tonight and got rave reviews! It was delish! I used peas and all the sauce. Also, i added more mozzarella cheese.
So happy you liked it!! Yes, that is the great thing about cooking. I love to bake, but you do have to be pretty exact. With cooking, you can add more or less of things to your taste.
OMG I do not like spaghetti squash, but I think I could get DOWN with this recipe! I’m so going to give it a try. Thanks so much for stopping by my facebook page!
The sauce is really good. Give the spaghetti squash a try, but if not, I am sure it would be great on regular pasta.
I am going to try this tomorrow night! Think I am going to use chicken sausage! SO YUMMY looking! Thanks!
I hope you like it! Let me know how it goes.