This Cheesy Spaghetti Squash Casserole is easy to prepare and makes a fantastic gluten-free dinner.
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Say what you want about casseroles, but you can’t deny the comfort of a warm dish of cheese and vegetables. If you have a thing about casseroles, you can call this something else if you want. Just know that when spaghetti squash, marinara sauce, and cheese come together, it’s a good thing.

I cooked my spaghetti squash a different way to make this. I cut the squash in rings before cooking them, based on this tutorial.

Cheesy Spaghetti Squash Casserole
- Total Time: 1 hour 20 mins
- Yield: 2 1x
Description
This Spaghetti Squash Casserole is easy to prepare and makes a great gluten-free dinner.
Ingredients
- 1 large spaghetti squash
- 1 cup marinara sauce or Instant Pot Spaghetti Sauce
- 1/3 cup nonfat Greek yogurt
- 2 cups part skim shredded mozzarella cheese, divided
- 1 teaspoon dried basil
- 1 teaspoon dried thyme
- 1/4 heaping teaspoon salt
- 1/4 teaspoon freshly ground black pepper
- 1/3 cup parmesan cheese
Instructions
- Preheat the oven to 400 degrees.
- Cut the squash into 1-inch rings and use a knife to cut out the inner ring with seeds.
- On 2 rimmed baking sheets lined with parchment paper or a silicone baking mat, cook the squash until it is tender and starting to brown, 30-40 minutes.
- Allow the squash to cool until is cool enough to handle.
- Using your fingers, separate the squash fibers from the hard outer shell and discard the shell.
- Place the squash fibers in a medium bowl and carefully separate them with your fingers.
- Add the marinara sauce, yogurt, 1 3/4 cup mozzarella cheese, basil, thyme, salt, and pepper and mix.
- Transfer the mixture to a medium baking dish.
- Top with the remaining mozzarella cheese and the parmesan cheese.
- Reduce the oven temperature to 350 degrees and bake for 25 minutes, or until the casserole is bubbly and the cheese is melted.
- Enjoy!
- Prep Time: 15 mins
- Cook Time: 1 hour 5 mins
- Category: main
Nutrition
- Serving Size: 1 of 2 servings
- Calories: 514
- Sugar: 9g
- Sodium: 1260mg
- Fat: 29.5g
- Carbohydrates: 31g
- Protein: 44g


Looks great! Does it really only serve 2?
It depends what you serve it with. Tim and I have bigger appetites, but for us it only served 2. 🙂
I was never a big casserole fan, but now it’s winter, and I am so busy juggeling work and having a kid that casseroles have become a new staple around here.
This one looks really yummy. I’m going to try this!
I hope you love this!