Deliciously cheesy spaghetti squash casserole makes a wonderful side dish and is filling enough to serve as a meatless main course.
This spaghetti squash casserole is one of my favorite recipes to make with this tasty root vegetable. It’s cheesy, delicious, and so easy to make! I started out making it whenever I had leftover cooked spaghetti squash. But it is so good, so tasty and filling, that now I make it whenever I get the chance.
The ingredients you’ll need
You’ll only need a few simple ingredients to make this tasty casserole. The exact measurements are included in the recipe card below. Here’s an overview of what you’ll need:
Spaghetti squash: I use a fairly large 3-lb. squash in this recipe.
Egg: I use large eggs in most of my recipes, this one included.
Sour cream: I tried once to use Greek yogurt instead and was underwhelmed. I think sour cream is better.
Minced garlic: Mince it yourself, or use the stuff that comes in a jar. Both work. Garlic powder (1 teaspoon) works too.
Kosher salt and black pepper: If using fine salt, you should reduce the amount you use, or the dish could end up too salty.
Dried thyme: Make sure it’s fresh! A stale spice can easily ruin a dish.
Shredded sharp cheddar: Another cheese that works great in this casserole is Gruyere.
How to make spaghetti squash casserole
It’s so easy! Scroll down to the recipe card for the detailed instructions. Here are the basic steps:
1. Cook the squash. I cook it in the microwave.
2. Scoop out the pulp and seeds, and rake a fork back and forth to remove strands of the flesh into a bowl.
3. Whisk together the remaining ingredients except for the cheese.
4. Add the squash strands and the cheese and mix until uniform.
5. Transfer to a greased baking dish and bake until browned, about 40 minutes at 400°F.
Reviews of this recipe
You can use this basic recipe and add all kinds of yummy things to it! Debbie, a reader of this blog, recently emailed me. She said:
I made your cheesy spaghetti squash casserole and it was delicious. I hate to get Allrecipes on you… but I added chicken, spinach, and mushrooms because I needed something really hearty to take to work. The base – your recipe – is excellent. I will use it again and again!
I love Debbie’s suggestions! And I can also see myself adding cooked ground beef to the mixture before baking it.
Like all casserole recipes, this one is flexible and forgiving. So go ahead and experiment with your own additions.
How to serve it
This tasty spaghetti squash casserole makes a wonderful side dish, but is also substantial and filling enough to serve as a meatless main dish.
What about leftovers?
Leftovers keep well in the fridge, in a sealed container, for up to 4 days. Reheat them gently, in the microwave on 50% power.
More tasty casserole recipes
Never miss a recipe!
I typically publish a new recipe once or twice per week. Want the new recipes in your inbox? Subscribe!
Cheesy Spaghetti Squash Casserole
- Olive oil cooking spray
- 1 3 lb. spaghetti squash, or 2 1/2 cups (450 grams) cooked spaghetti squash
- 1 large egg
- 1/2 cup sour cream
- 1 teaspoon Diamond Crystal kosher salt
- 1/4 teaspoon black pepper
- 1/2 teaspoon dried thyme
- 1 tablespoon minced garlic
- 1 cup shredded sharp cheddar cheese
- Preheat oven to 400 degrees F. Lightly spray a 1.5-quart baking dish with olive oil cooking spray.
- If you need to cook the spaghetti squash: Pierce the spaghetti squash in a few spots with a sharp knife. Microwave 6 minutes; turn to the other side and microwave 6 more minutes, until soft to the touch. Let stand for 5 minutes to finish cooking. Using a sharp knife, cut the spaghetti squash in half lengthwise. Allow to cool 5 minutes, until easier to handle. Scoop out the pulp and seeds from the center, then rake a fork back and forth to remove strands of the flesh onto a bowl. Set aside.
- In a large bowl, lightly whisk the egg. Add the sour cream, kosher salt, black pepper, dried thyme and minced garlic. Whisk until smooth.
- Mix in the cooked spaghetti squash and the shredded cheese.
- Transfer the mixture to the prepared baking dish. Bake until browned, about 40 minutes (it will smell wonderful!).
- Allow to cool 10 minutes, then scoop into plates, or if you’re patient, carefully cut into squares and serve.