This cheesy spaghetti squash casserole is one of those recipes I turn to when I want comfort food that doesn’t weigh me down. It works beautifully as a side dish, but if I’m being honest, I’ve had it plenty of times as a main. It’s cozy, satisfying, and somehow manages to feel both indulgent and wholesome at the same time.
Why This Recipe Is Always On My Menu
I first made this casserole on a lazy Sunday with some leftover roasted spaghetti squash sitting in the fridge. I didn’t want to waste it, so I tossed it with some sour cream and cheddar, popped it in the oven, and hoped for the best. And wow — it was a hit. Now, it’s something I make intentionally, especially when I want a low-carb, cheesy bake that doesn’t leave me missing the pasta.
One of the things I love most? You can bulk it up with extra veggies, protein, or whatever bits you’ve got left in the fridge. It’s that kind of dish — forgiving, flexible, and flavorful.
What You’ll Need
Here’s what I usually use, but don’t be afraid to play around with your own mix-ins:
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Spaghetti squash – About 3 pounds is perfect. I usually roast mine, but if I’m short on time, microwaving works fine too.
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Full-fat sour cream – The creaminess you get from full-fat is unbeatable. If I’m out, I’ve used softened cream cheese with good results.
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Egg – Helps hold everything together. Without it, the casserole is softer but still delicious.
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Dried thyme, salt, and pepper – Simple seasonings that don’t overpower. You could switch thyme with oregano or even Italian seasoning.
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Shredded sharp cheddar – I love the punchiness of sharp cheddar, but if I’m feeling fancy, Gruyère or smoked Gouda adds a nice twist.
Ways I Like To Change It Up
This casserole is basically a blank canvas — I switch it up all the time depending on what’s in the fridge:
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Add sautéed spinach or mushrooms for a veggie boost.
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Toss in some leftover grilled chicken to make it a meal.
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Stir in crispy bacon bits if you’re craving that smoky crunch.
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Sprinkle a bit of parmesan on top before baking for a golden, salty finish.
Let’s Get Cooking
Here’s how I make it — no fuss, no fancy steps:
First, I cook the squash — usually roasted whole, then halved and cooled enough to handle. Scoop out the seeds, then use a fork to shred the flesh into spaghetti-like strands. You’ll need about 3 cups.
In a big bowl, I whisk together an egg, sour cream, thyme, salt, and pepper. Then I fold in the squash and shredded cheese until it’s all well mixed.
Grease a baking dish, pour in the mixture, and smooth the top. I bake it at 400°F for around 40 minutes, or until the top is golden and bubbly.
Let it cool slightly — it firms up as it rests — and then slice into squares or spoon it onto plates.
Helpful Tip From My Kitchen
If you’re skipping the egg, add a bit more sour cream (around ¾ cup total). The casserole will be softer and scoopable instead of firm enough to slice, but still super tasty. I’ve done this version when I was low on eggs and it worked out just fine.
Frequently Asked Questions
Do I need to add flour?
Not at all. The egg and sour cream do the job of binding without needing any flour.
Do I have to cook the squash first?
Yes — raw squash won’t work here. Roasting or microwaving softens it enough to shred and mix.
Can I use Greek yogurt instead of sour cream?
You can. I’ve tried it in a pinch. It’s tangier and a bit less rich, but still tasty.
Can I double it?
Absolutely. Just use a larger baking dish and add a few extra minutes to the bake time.
How I Serve It
This casserole is filling enough to stand on its own, especially if I bulk it up with chicken or bacon. But I often serve it alongside something that bakes at the same temp — makes dinner easier.
Some go-to pairings from my weeknight rotation:
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Oven-baked chicken thighs
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Spicy jerk chicken
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Pork meatballs
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Baked drumsticks
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Ground beef casserole
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Even leftover rotisserie chicken works great
It’s also a hit at potlucks — it travels well and reheats beautifully.
Cheesy Spaghetti Squash Casserole
If you're looking for a cozy, comforting side dish—or even a satisfying vegetarian main—this cheesy spaghetti squash casserole might just become a regular on your table.
Ingredients
- 1 tablespoon fresh garlic, finely minced
- ½ teaspoon dried thyme
- ½ cup sour cream
- 1 large egg
- 1 cup shredded sharp cheddar cheese
- ¼ teaspoon ground black pepper
- Olive oil spray, for greasing
- 1 teaspoon kosher salt (or ½ tsp if using fine salt)
- 1 medium spaghetti squash (about 3 pounds), or 2½ cups cooked squash strands
Instructions
- Preheat the oven: Set your oven to 400°F and lightly grease a 1.5-quart baking dish with olive oil spray. This keeps the casserole from sticking and helps with cleanup later.
- Cook the squash: Using a sharp knife, pierce the spaghetti squash in several spots to allow steam to escape. Microwave it on one side for about 6 minutes, then flip and microwave for another 6 minutes. Let it rest for 5 minutes after cooking.
- Once it’s cool enough to handle, slice the squash in half lengthwise. Scoop out the seeds and center strings, then use a fork to pull the spaghetti-like strands into a large bowl. Set aside.
- Mix up the filling: In a separate mixing bowl, beat the egg lightly. Add sour cream, minced garlic, thyme, salt, and pepper. Stir until smooth and combined. Fold in the cooked spaghetti squash strands and cheddar cheese until everything is evenly coated.
- Bake the casserole: Spoon the mixture into your prepared baking dish. Spread it out evenly and pop it into the oven. Bake for around 40 minutes, or until the top is golden and bubbling. Your kitchen will smell amazing at this point!
- Cool before serving: Once baked, let the casserole rest for 10 minutes to firm up. Then scoop it out or cut into squares and serve warm.
Notes
- Want to bulk it up? Add a cup of cooked, shredded chicken and an extra spoonful of sour cream to make it a hearty main.
- Sneak in more veggies—stir in some sautéed mushrooms, onions, or even wilted spinach for extra flavor and texture.
- No egg? No problem. You can skip it by increasing the sour cream to ¾ cup. It won’t hold shape as neatly, but still tastes just as comforting.
- Feeding a crowd? Double the ingredients and use a 9x13-inch dish. It’s great for potlucks or meal prep.
- Leftovers keep well for up to 4 days in the fridge. Reheat gently in the microwave at half power. You can also freeze individual portions for up to 3 months.
Nutrition Information
Yield
4Serving Size
1Amount Per Serving Calories 432Total Fat 30gSaturated Fat 15gTrans Fat 1gUnsaturated Fat 11gCholesterol 120mgSodium 751mgCarbohydrates 23gFiber 5gSugar 10gProtein 19g
Dinnerfocus.com, occasionally offers nutritional information for recipes contained on this site. This information is provided as a courtesy and is an estimate only. This information comes from online calculators. Although allchickenrecipes.com attempts to provide accurate nutritional information, these figures are only estimates.
Leftovers and Storage Tips
I pack any extras into a glass container and pop it in the fridge — it stays good for about 4 days. I usually reheat it in the microwave at 50% power so the cheese doesn’t dry out.
If you want to freeze it, let it cool completely, then wrap the whole dish (or individual portions) in plastic wrap and foil. It keeps well for up to 3 months.
A recent leftover night looked like this: reheated spaghetti squash casserole, a few baked ribs from the freezer, and some crunchy pickled okra. Simple, satisfying, and zero waste.
If you love spaghetti squash and want something comforting that doesn’t feel heavy, this cheesy bake is totally worth making. I always feel a little better about dinner when I know there’s some extra veggies baked right in.
Try other Spaghetti Squash recipes:
