Spaghetti Squash Casserole
This post may contain affiliate links. See my disclosure policy.
My spaghetti squash casserole features ‘noodles’ baked in an irresistibly cheesy cream sauce with tender chicken until hot and bubbly. It’s such a cozy weeknight dinner.
When the cooler months roll around, I learn hard into comfort meals, and this spaghetti squash casserole is one of the first things I make. It’s become a cozy weeknight staple in our house, especially when we want something warm and cheesy but still lighter than traditional pasta or lasagna.
Spaghetti squash gets a bad reputation for being bland and watery. After testing a few different methods over the years, I learned the secret is baking it into a creamy, cheesy sauce. It keeps the strands tender, not soggy, and turns the squash into something even my picky partner would gladly enjoy seconds of.
Once the squash is cooked and scraped, I mix it in a rich, protein-packed sauce (I often add shredded chicken to make it a full meal, but it’s just as delicious without). It’s then baked until hot and bubbling.
We usually enjoy it with garlic bread or dinner rolls, but it’s also great over rice or with a simple green salad when we want something lower carb.
Table of Contents
Recipe highlights
- Secretly low carb. My partner and I love using spaghetti squash in casseroles because it tastes just as comforting and satisfying as regular pasta noodles, but doesn’t weigh you down.
- Customize it! Picky eaters at home? No problem! You can easily personalize the casserole by switching up the veggies, cheeses, or meats to make everybody happy. It’s even easier to make a vegetarian version!
- Easy to make ahead. I like to make this casserole a few days ahead of time, then pop it in the oven for busy weeknight dinners or when I’m too tired to cook.
Key Ingredients
I’m also including substitutions and some kitchen notes. The complete list with measurements is in the recipe card below.
- Spaghetti squash. This is one of my favorite winter squashes to use in low-carb dinners. After baking, the spaghetti squash flesh becomes long, stringy, and tender, just like regular spaghetti. Of course, classic spaghetti noodles also work.
- Olive oil. You need to add some fat to the squash as it roasts to avoid it drying out. I typically use olive oil, but butter works.
- Onion and garlic. A tasty duo that adds delicious savory notes to every bite.
- Chicken breasts. Leftover or pre-cooked chicken breasts are a savior, and I typically use my Instant Pot chicken breasts or Instant Pot shredded chicken. If I’m desperate, store-bought rotisserie chicken is a lifesaver.
- Mozzarella cheese. I recommend shredding the mozzarella straight from the block. It’s much smoother and creamier than pre-shredded cheese. Other cheese options work too, including cheddar and parmesan.
- Blue cheese dressing. Adds an extra level of creaminess and the subtle savory flavor of the blue cheese. Opt for a brand that has minimal ingredients, like Ken’s Steakhouse or Lighthouse.
- Cream cheese. It adds an extra layer of creaminess and a subtle tanginess. Please, friends- use full-fat cream cheese for the ultimate texture.
How to make spaghetti squash casserole
Step 1- Prep the spaghetti squash: Place the seasoned squash halves, cut side down, on a baking sheet and roast until fork-tender. Let them cool slightly, then scrape the flesh with a fork to loosen the “spaghetti” strands.
Tip: You can also use my air fryer spaghetti squash recipe.
Step 2- Make the sauce: Sauté the onions and garlic in a large oiled skillet. Add the shredded chicken, then the blue cheese dressing, cream cheese, and mozzarella. Stir until smooth and creamy.
Step 3- Assemble and bake: Combine the spaghetti squash strands and cream sauce in a large baking dish. Bake until the top is lightly golden brown.
Step 4- Remove from the oven, sprinkle the top with basil, then serve!
Arman’s recipe tips
- Slice the squash easily. I like to pierce the outside of the squash with a fork, then zap it in the microwave for 1 to 2 minutes. This technique, along with a very sharp knife, makes it much easier to slice in half.
- Let it rest after baking. Once it’s out of the oven, set the casserole aside for 5 to 10 minutes to cool. This helps the flavors meld together and gives it time to firm up, making it easier to scoop and serve.
- Use pre-shredded squash. I’ve noticed more and more grocery stores selling packages of already-shredded spaghetti squash, which is such a time saver. If it’s frozen, thaw it first to avoid a watery casserole.
Ways I’ve changed things up
I’ve been making this casserole for years, and over time, I’ve had some fun changing up the flavor. Here’s what I’ve tried:
- Switch up the meat. Instead of making a spaghetti squash chicken casserole, try it with cooked ground beef (I LOVE using taco meat), Italian sausage, ground turkey, or the leftover Thanksgiving turkey tenderloin! Even chopped bacon or pancetta in the sauce would make this dish extra succulent.
- Make it tomato-based. I like to give this casserole a Mediterranean spin by adding cherry tomatoes, sliced olives, and zucchini strips. Also, swap out the blue cheese dressing for marinara sauce.
- Make it meatless. Make a vegetarian spaghetti squash casserole by substituting the chicken for a can of cannellini beans, sliced tofu, or a medley of cooked veggies.
Storage instructions
To store: Store leftovers in an airtight container in the refrigerator for 3 to 4 days.
To freeze: Place the casserole in an airtight freezer-safe container and store it in the freezer for 2 to 3 months. Let it thaw in the fridge overnight or reheat it right from frozen in the oven.
Make ahead: To prepare the squash casserole in advance, assemble it in the casserole dish and cover it with a lid or a layer of plastic. Refrigerate it for up to 3 or 4 days, then bake as normal.
Plate it up
I like to serve my spaghetti squash casserole as the main dish for well-balanced family dinners. It’s delicious with a side of garlic bread to soak up the delicious sauce, as well as simple side salads and air fryer asparagus, sauteed broccolini, or microwave baked potato.
Frequently asked questions
Yes, you can roast spaghetti squash up to 4 days ahead of eating it. After roasting and scraping the flesh into strands, let it cool to room temperature and store it in an airtight container in the refrigerator.
Yes! After cooking and scraping the flesh into strands, let the squash cool to room temperature. Transfer the strands to a freezer-safe container and freeze for 2 to 3 months. Thaw the spaghetti squash in the fridge before using it in casseroles.
✅ Nutrition reviewed
Nutrition information has been reviewed by registered dietitian Felicia Newell, MScAHN, RD, CPT.
Spaghetti Squash Casserole
Video
Ingredients
- 1 medium spaghetti squash
- 2 tablespoons olive oil
- 1/2 teaspoon salt
- 1/2 teaspoon pepper
Casserole
- 1 tablespoon olive oil
- 1/2 small red onion thinly sliced
- 2 cloves garlic minced
- 3 cups chicken breast cooked and shredded
- 1 cup blue cheese dressing
- 1 cup cream cheese
- 2 cups mozzarella cheese
- 1/4 cup basil
Instructions
- Preheat your oven to 190C/375F.
- Carefully cut the spaghetti squash in half lengthwise. Scoop out the seeds and stringy bits from the center.
- Brush the cut sides of the spaghetti squash with olive oil and season with salt and pepper. Place the squash halves, cut side down, on a baking sheet and bake for 30 minutes or until the squash is tender.
- Once cooked, use a fork to scrape the flesh of the squash into spaghetti-like strands. Set aside.
- In a large skillet, heat the olive oil over medium heat. Add the chopped red onions and minced garlic, and sauté until they become fragrant. Add the shredded chicken breasts and cook until they are heated through. Stir in the Blue Cheese dressing, cream cheese, and shredded mozzarella until the cheeses are fully melted and the sauce is smooth.
- In a large casserole dish, combine the cooked spaghetti squash strands and the creamy sauce mixture. Mix everything together until well combined. Bake in the oven for 20 minutes, until bubbling and the top is lightly golden.
- Remove from the oven and sprinkle the chopped basil on top.
Notes
- Leftovers: Keep in the fridge for up to 4 days or the freezer for up to 3 months.
- Make ahead: To prepare the squash casserole in advance, assemble it in the casserole dish and cover it with a lid or a layer of plastic. Refrigerate it for up to 3 or 4 days, then bake as normal.
Nutrition
More healthy casserole recipes
- French Onion Chicken Casserole
- Philly Cheesesteak Casserole
- Broccoli Cheese Rice Casserole
- Easy Tuna Casserole
- Chili relleno casserole
- Butternut squash casserole
- Cauliflower casserole
Recipe updated
I originally published this recipe in October 2023, but updated it in November 2025 to include serving ideas and quicker ways to cook the squash. The cooking time has also been amended. No measurements or ingredients have changed.
This turned out delicious! Never tried this before.
So glad you enjoyed it! Such a versatile veggie this one.
This is decadent.Sooooo good.Thank you.Keto is much easier with your tasty recipes.My son asks if I am making Big Man’s recipe for dinner lol.2 fans.
That didn’t look like a spaghetti squash in the video. Was it a butter nut squash? Love spaghetti squash
Where csn I find blue cheese dressing? Do you know?
This was amazing. Great combination of flavors, great texture, and easy.
So great to hear that!