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This image shows a golden-brown spaghetti squash casserole in a baking dish, topped with melted cheese, ready to be served.]

Spaghetti Squash Casserole Recipe

This Cheesy Spaghetti Squash Casserole is a delightful blend of flavors and textures, combining creamy sour cream and sharp cheddar cheese with the unique strands of spaghetti squash. It's perfect as a side dish or a hearty meatless main course. Plus, the leftovers reheat beautifully in the microwave!
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Prep Time 15 minutes
Cook Time 40 minutes
Rest time 10 minutes
Total Time 1 hour 5 minutes
Course Side Dish
Cuisine American
Servings 4
Calories 225 kcal

Ingredients
  

  • Olive oil cooking spray
  • 1 3 pounds Raw spaghetti squash (or 2½ cups cooked spaghetti squash)
  • 1 Large egg
  • ½ cup Sour cream
  • 1 tsp Diamond Crystal kosher salt or ½ teaspoon of any other salt
  • ¼ tsp Black pepper
  • ½ tsp Dried thyme
  • 1 tbsp Fresh garlic minced
  • 1 cup sharp Cheddar cheese shredded

Instructions
 

  • Preheat your oven to 400°F (200°C). Lightly spray a 1.5-quart baking dish with olive oil cooking spray.
  • Pierce the spaghetti squash in a few spots with a sharp knife. Microwave it for 6 minutes, then turn it to the other side and microwave for an additional 6 minutes until it’s soft to the touch. Let it stand for 5 minutes to finish cooking.
    This image shows a cooled spaghetti squash being cut in half lengthwise, revealing its soft, stringy flesh inside.]
  • Carefully cut the spaghetti squash in half lengthwise after it has cooled for 5 minutes. Scoop out the pulp and seeds from the center, then rake a fork back and forth to separate the strands into 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.
  • Stir in the cooked spaghetti squash and shredded cheddar cheese until well combined.
  • Transfer the mixture to the prepared baking dish and bake until browned, about 40 minutes. The casserole will smell wonderful as it bakes!
  • Allow the casserole to cool for 10 minutes. You can then scoop it onto plates or carefully cut it into squares to serve.
    This image shows the baked spaghetti squash casserole cooling on a counter, ready to be scooped onto plates or cut into squares.]

Notes

  • Veggie Additions: Feel free to add more veggies! Consider mixing in ½ cup of sautéed spinach (drain it well), ½ cup of sautéed mushrooms, ¼ cup of sautéed onions, or ¼ cup of chopped green onions for extra flavor and nutrition.
  • For a Complete Meal: You can also add 1 cup of cooked and shredded grilled chicken breast plus an extra ¼ cup of sour cream to turn this casserole into a complete meal.