Spaghetti Squash Casserole – The Big Man’s World ®

This spaghetti squash casserole takes comforting weeknight dinners to a new level! Spaghetti squash “noodles” are baked in an irresistibly cheesy cream sauce with tender chicken until hot and bubbly. The perfect low carb comfort food for family dinners!

I absolutely love fall and all of the amazing comfort foods that come with it! Just like my zucchini casserole or butternut squash casserole, this spaghetti squash casserole recipe is a go-to comfort meal in our household as soon as the cold weather hits.

Spaghetti squash gets a bad wrap for being bland and tasteless, but like most foods, it comes down to how to use it. Baking it in a cheesy casserole completely transforms it into something impressive.

Why this recipe works

• The ultimate low carb comfort food. Our family loves 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 easy to make a vegetarian version!
• All about convenience. You’ll love how effortless it is to put together and bake. 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. 

Ingredients needed

This dish is all about comfort but doesn’t call for any complicated ingredients. Here is everything you’ll need:

• Spaghetti squash. This is one of my favorite kinds of winter squash to use in low carb dinners. After baking, the spaghetti squash flesh becomes long, stringy, and tender, just like regular spaghetti.
• Olive oil. This adds a rich flavor and prevents the squash flesh from drying out as it roasts.
• Salt and pepper. To taste. 
• Onion and garlic. A tasty duo that adds delicious savory notes to every bite.
• Chicken breasts. I like to bake chicken breasts myself in advance or use the leftover shredded chicken already in my fridge. If you’re all out, an easy alternative is to shred a store-bought rotisserie chicken.
• 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 cheese and parmesan cheese.
• 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 Litehouse.
• Cream cheese. It adds an extra layer of creaminess and a subtle tanginess. 
• Fresh basil. For garnish.

How to make spaghetti squash casserole

This comforting fall casserole is easy to put together in just 4 simple steps:

Cut and season the squash: Cut the spaghetti squash in half lengthwise, scoop out the seeds and stringy fibers, and season the cut sides with olive oil, salt, and pepper.  

Roast the spaghetti squash: Place the 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. 

Make the sauce: Saute 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. 

Assemble and bake: Combine the spaghetti squash strands and cream sauce in a large baking dish. Bake until the top is lightly golden brown. Remove from the oven, sprinkle the top with basil, then serve!

Recipe tips and variations

• 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.
• Switch up the meat. Instead of making a spaghetti squash chicken casserole, try it with cooked ground beef, Italian sausage, ground turkey, or the leftover Thanksgiving turkey! Even chopped bacon or pancetta in the sauce would make this dish extra succulent.
• Make it tomato-based. 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.

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