Spaghetti Squash Casserole with mushrooms, creamy goat cheese sauce, and crispy Parmesan topping. Enjoy this low-carb baked spaghetti squash casserole as a side dish or the main event.

Course: Entree, Main Course
Cuisine: American
Diet: Vegetarian


Prep Time: 20 minutes
Cook Time: 1 hour
Total Time: 1 hour 30 minutes


Servings: 5


Calories: 296kcal


  • Large skillet
  • 8×8 or 9×9 inch baking dish


  • 6 cups spaghetti squash strands from 2 small (2 lb.) squashes or 1 large (4 lb.) squash
  • 2 Tbsp. olive oil
  • 8 oz. sliced cremini (baby bella) mushrooms
  • ½ cup chopped shallots
  • 1 Tbsp. minced fresh garlic
  • ¼ tsp. red pepper flakes
  • 2 cups fresh baby spinach
  • 3 Tbsp. all-purpose flour
  • 1 cup chicken or vegetable broth
  • 1 cup milk of choice (I use unsweetened cashew or almond milk)
  • ½ tsp. kosher salt
  • ¼ tsp. black pepper
  • 1 Tbsp. fresh thyme leaves
  • 1 (4-oz.) log goat cheese, softened

Panko-Parmesan Topping

  • 1 Tbsp. butter
  • ½ cup plain Panko breadcrumbs
  • ½ cup grated Parmesan cheese


  • Preheat oven to 375ºF. Slice the squash in half lengthwise and scoop out the seeds. Rub oil onto the flesh, or lightly coat with non-stick cooking spray. Place squash halves, flesh side-down, on a baking sheet lined with foil.

    For two small squashes, bake for 35 to 40 minutes. For one large squash, bake for 45 to 50 minutes, or until the flesh of the squash is easily pierced with a fork.

    When cool enough to handle, pull the squash strings out of the squash’s center with a fork and transfer to a large bowl.

  • In a large skillet, heat 2 Tbsp. oil over medium-high heat. Once hot, add the mushrooms and shallots; cook 6 to 7 minutes, or until soft. Add garlic, red pepper flakes, and spinach; cook 1 to 2 minutes, stirring often, until the spinach wilts down.
  • Whisk in the flour and cook for 2 FULL minutes. Slowly stream in the broth and milk, whisking constantly, until the liquids are fully combined. Simmer mixture for 5 to 6 minutes, until thickened. Season with salt, pepper, and fresh thyme.
  • Add the goat cheese and cook for 2 to 3 more minutes, stirring often, until the goat cheese melts and melds into the mixture. Once the sauce is smooth, add the spaghetti squash strands. Use a pair of tongs to toss squash with the sauce until everything is well-combined.
  • Grease an 8×8 or 9×9 inch baking pan with non-stick cooking spray or butter. Transfer the spaghetti squash casserole filling to the baking dish and set aside.
  • Wipe the skillet clean and return to medium-high heat. Add 1 Tbsp. butter. Once melted, add the Panko breadcrumbs and lightly toast for 3 to 5 minutes, or until slightly golden. (Watch closely to avoid burning.) Transfer breadcrumbs to a bowl and toss with Parmesan cheese. Sprinkle the Panko-Parmesan mixture over the spaghetti squash casserole.

    Bake casserole at 375ºF, uncovered, for 25 minutes, or until bubbly and golden. Remove from oven and let sit for 10 minutes before serving. Serve with extra fresh thyme, if desired.


    To Make Ahead. Spaghetti squash can be roasted, shredded, and stored in an airtight container for up to 3 days ahead. This will save you up to an hour when you’re ready to prepare the casserole.

    To Store. Store leftovers in the refrigerator for up to 4 days.

    To Reheat. Either reheat individual portions in the microwave, or place the whole pan back in the oven at 350ºF until warmed through.


    Serving: 1.2cups | Calories: 296kcal | Carbohydrates: 26g | Protein: 14g | Fat: 17g | Saturated Fat: 5g | Sodium: 640mg | Fiber: 5g | Sugar: 6g