This Cheesy Spaghetti Squash Casserole is one of my favorite go-to comfort dishes. It turns tender roasted spaghetti squash into a creamy, cheesy, and hearty casserole that feels indulgent without being heavy. I love how satisfying and simple it is to prepare, yet impressive enough to serve to guests.

Why You’ll Love This Recipe

I love this recipe because:

It’s a lighter, low-carb alternative to pasta-based casseroles.
It’s rich and comforting thanks to the blend of cheeses.
It’s easy to prepare with simple, everyday ingredients.
It’s perfect for making ahead of time.
It’s versatile—I can add proteins or veggies to suit my mood.

Ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

1 medium spaghetti squash (about 2 to 3 pounds)
2 cups shredded mozzarella cheese
1 cup ricotta cheese
1 cup grated Parmesan cheese
1 large egg
2 cloves garlic, minced
1 teaspoon Italian seasoning
½ teaspoon salt
¼ teaspoon black pepper
1 cup marinara sauce (optional, for layering)
Fresh parsley, chopped (optional, for garnish)

Directions

Preheat the oven to 400°F (200°C).
Cut the spaghetti squash in half lengthwise and scoop out the seeds.
Place the halves cut-side down on a baking sheet and roast for 30 to 35 minutes, until the flesh is tender.
Let the squash cool slightly, then use a fork to scrape the flesh into spaghetti-like strands. Transfer the strands to a large mixing bowl.
Add the shredded mozzarella, ricotta, Parmesan, egg, garlic, Italian seasoning, salt, and black pepper to the bowl. Mix until everything is well combined.
Lightly grease a 9×13-inch baking dish. If using marinara sauce, spread a thin layer on the bottom of the dish.
Spread the squash mixture evenly into the baking dish.
Sprinkle additional mozzarella and Parmesan on top.
Bake for 15 to 20 minutes, until the cheese is melted and golden brown.
Let it cool for a few minutes, garnish with parsley if desired, and serve warm.

Servings and Timing

Servings: 6 to 8
Prep time: 15 minutes
Cook time: 45 minutes
Total time: About 1 hour

Variations

Add cooked ground turkey, chicken, or Italian sausage for extra protein.
Stir in sautéed mushrooms, spinach, or bell peppers for more veggies.
Use cheddar, gouda, or a spicy pepper jack instead of mozzarella for a flavor twist.
Swap the marinara sauce with pesto or a creamy Alfredo sauce for a different base.
Make it spicy by adding crushed red pepper flakes or diced jalapeños.

Storage/Reheating

Storage: I store leftovers in an airtight container in the fridge for up to 5 days.
Freezing: It freezes well. I portion it into individual servings, wrap them tightly, and freeze for up to 3 months.
Reheating: I reheat in a preheated oven at 350°F (175°C) until hot, or microwave single servings for 1-2 minutes.

FAQs

What can I serve with this casserole?

I usually pair it with a side salad or steamed vegetables. Garlic bread or crusty rolls also go great with it.

Can I make this ahead of time?

Yes, I often assemble it a day in advance and refrigerate it. When ready, I just bake it before serving.

Is this recipe gluten-free?

Yes, all the ingredients are naturally gluten-free. Just be sure to check that your marinara sauce is also gluten-free if using.

Can I use pre-cooked spaghetti squash?

Absolutely. If I have leftover roasted spaghetti squash, I just skip the roasting step and jump straight to mixing it with the cheese blend.

Can I double the recipe?

Yes, I’ve doubled it for larger gatherings. Just use a larger baking dish and adjust the baking time slightly to ensure it heats through.

Conclusion

This Cheesy Spaghetti Squash Casserole is one of those dishes I keep coming back to. It’s cozy, easy, and endlessly customizable. Whether I’m cooking for the family or prepping for a week of meals, it never fails to satisfy. I hope you enjoy it as much as I do!