Cheesy Baked Spaghetti Squash Casserole

Cheesy, satisfying Baked Spaghetti Squash Casserole—an easy, low‑carb weeknight dinner that’s filling and makes excellent leftovers.

Happy (almost) Friday! If you’re looking for a simple way to swap pasta for a lighter option without sacrificing comfort-food flavor, spaghetti squash is a fantastic choice. When roasted and shredded, its strands resemble angel hair pasta and absorb sauces beautifully. The squash itself is mild in flavor, so it pairs with everything from a classic marinara to a creamy sauce. This baked casserole layers roasted spaghetti squash with a rich meat sauce, a touch of Parmesan, fresh basil, and melty mozzarella for a dish that feels indulgent but stays on the lighter side.

This casserole is versatile: skip the ground beef for a vegetarian version, or substitute lean ground turkey if you prefer. The homemade meat sauce in this recipe is hearty and flavorful on its own, so it stands up well whether you serve it with the squash, spoon it over greens, or toss it with whole‑grain pasta for a different meal. It’s also a great way to add an extra serving of vegetables to family meals, and the recipe yields plenty of leftovers for lunches or quick dinners.

One of the best parts is that much of the work can be done ahead. Roast the squash and prepare the sauce a day or two in advance; assemble the casserole, refrigerate, and add the cheese just before baking. This makes weeknight dinners much easier when time is tight.

Baked Spaghetti Squash Casserole

Cheesy and delicious—perfect for a low‑carb weeknight dinner with plenty of leftovers.

• Prep Time: 10 mins
• Cook Time: 1 hr 20 mins
• Total Time: 1 hr 30 mins
• Servings: 10

Ingredients

• 2 ripe spaghetti squash
• 1 Tbsp olive oil
• 1 onion, diced
• 2 cloves garlic, minced
• 1 pound lean ground beef (95% lean) — or substitute ground turkey or omit for vegetarian
• 2 cups crushed tomatoes
• 1 (8 oz) can tomato sauce
• 1/2 cup low‑sodium chicken broth (or vegetable broth)
• 1 tsp Italian seasoning
• 1 packet Stevia (or 1 tsp sugar, optional)
• Salt and pepper, to taste
• 2 Tbsp freshly grated Parmesan cheese
• 3 Tbsp fresh basil, chopped (divided use)
• 1 cup shredded mozzarella cheese

Instructions

1. Preheat the oven to 350°F (175°C). Cut each spaghetti squash in half lengthwise and scoop out the seeds. Place the halves cut‑side down on a baking sheet lightly sprayed with oil so they don’t stick.
2. Bake the squash for about 45 minutes, or until the flesh is tender and easily shredded with a fork.
3. While the squash bakes, heat the olive oil in a large skillet over medium heat. Add the diced onion and minced garlic and sauté until fragrant, about 2 minutes.
4. Add the ground beef to the pan and cook until no longer pink, breaking it up as it cooks. Drain any excess fat if necessary.
5. Stir in the crushed tomatoes, tomato sauce, chicken or vegetable broth, Italian seasoning, Stevia (or sugar), and salt and pepper. Bring the sauce to a boil, then reduce the heat and let it simmer while the squash finishes baking.
6. When the sauce is nearly ready, stir in the grated Parmesan and 2 tablespoons of the chopped basil. Continue to simmer briefly so the flavors meld.
7. Remove the baked squash from the oven and use a fork to scrape out the strands into a large bowl.
8. In a 9×13‑inch baking dish, spread 1½ cups of the meat sauce over the bottom. Layer half of the spaghetti squash over the sauce, then add another 1½ cups of sauce. Add the remaining squash, top with the remaining sauce (about 1½ cups), and sprinkle the shredded mozzarella evenly over the top.
9. Cover the dish with foil and bake at 350°F for 30 minutes. Remove the foil and bake an additional 10 minutes, or until the cheese is melted and bubbly.
10. Garnish with the remaining tablespoon of fresh basil, serve hot, and enjoy.

Notes & Tips

• To save time, roast the squash and make the sauce a day or two ahead. Assemble the casserole before baking and refrigerate; add the mozzarella when you’re ready to bake.
• For a lighter version, use ground turkey or chicken, or omit meat and boost the sauce with extra vegetables like mushrooms, zucchini, or bell peppers.
• If you prefer a bit of heat, add red pepper flakes to the sauce.

Nutrition (per 1/2 cup serving)

Calories: 200 kcal | Carbohydrates: 12 g | Protein: 18 g | Fat: 8.1 g | Saturated Fat: 3.5 g | Fiber: 2.8 g | Sugar: 6.3 g

Nutrition information is automatically calculated and should be used as an approximation.

This baked spaghetti squash casserole is a family‑friendly recipe that delivers the comfort of baked pasta with fewer carbs and extra vegetables. It reheats well, making it ideal for meal prep or packed lunches. If you try it, leave a comment with your favorite variations or tips—I’d love to hear what you think.