Spaghetti Squash Casserole
Spaghetti squash casserole is a lighter, veggie-forward take on a classic baked pasta dish, made with tender strands of roasted spaghetti squash, lean ground turkey, marinara sauce, and melted cheese. It delivers all the cozy, comforting flavors you expect from a casserole while swapping traditional pasta for spaghetti squash to keep it gluten-free and more balanced.

This post may contain affiliate links which won't change your price but will share some commission.
A Quick Look at the Recipe
✅ Recipe Name: Spaghetti Squash Casserole
🕒 Ready In: ~1 hour 10 minutes
👪 Serves: 6 servings
🍽 Calories: ~360 per serving (estimated)
🥣 Main Ingredients: Spaghetti squash, ground turkey, marinara sauce, mozzarella
📖 Dietary Info: Gluten-free; lighter comfort food
👌 Difficulty: Easy - roast, mix, bake
SUMMARIZE & SAVE THIS CONTENT ON
This recipe is baked in two simple stages to ensure the squash is tender without becoming watery, then combined with a savory turkey marinara and finished with a bubbly cheese topping. It's a satisfying, family-friendly dinner that works well for weeknights, meal prep, or anyone looking for a comforting casserole that doesn't feel heavy.
If you enjoy lighter comfort food dinners like this, you may also like our Air Fryer Chicken Tenders, Homemade Hamburger Helper, or Zucchini Pizza Boats that are easy to make and great for busy weeknights.
Jump to:
- A Quick Look at the Recipe
- Why You'll Love This Spaghetti Squash Casserole:
- Key Ingredients:
- Easy Substitutions & Variations:
- How to Make Spaghetti Squash Casserole:
- Recipe Notes & Tips:
- How to Store:
- Spaghetti Squash Casserole FAQs:
- More Easy Dinner Recipes You'll Love
- Get a FREE Healthy Meal Planning Ebook
- Spaghetti Squash Casserole
Why You'll Love This Spaghetti Squash Casserole:
Comforting without the heaviness: Spaghetti squash replaces pasta for a lighter take on a classic baked casserole.
Protein-packed: Ground turkey adds protein and makes the dish filling enough for dinner.
Simple, familiar flavors: Marinara sauce, garlic, and melted cheese keep the flavors cozy and approachable.
Naturally gluten-free: Made without pasta, this casserole works well for gluten-free households.
Great for leftovers: Reheats well and makes an easy option for meal prep or next-day dinners.
Key Ingredients:
- spaghetti squash. When roasted, the flesh turns into tender, noodle-like strands that soak up the sauce beautifully. Be sure not to overcook it to avoid excess moisture.
- ground turkey. A lean protein that keeps the casserole light. Ground chicken or beef can be swapped in depending on what you have on hand.
- marinara sauce. Choose a high-quality or homemade Marinara Sauce with simple ingredients. Look for one without added sugar to keep things wholesome.
- mozzarella cheese. Melts into a gooey, cheesy topping. Use part-skim for a lighter option or whole milk for extra richness.
Scroll to the recipe card at the bottom of this page for exact quantities.
Easy Substitutions & Variations:
- Use a different protein: Ground chicken or lean ground beef can be used in place of ground turkey.
- Make it vegetarian: Skip the meat and add sautéed mushrooms, zucchini, or spinach to the marinara mixture.
- Change the cheese: Swap mozzarella for part-skim mozzarella, provolone, or an Italian cheese blend.
- Add extra seasoning: A pinch of red pepper flakes or dried basil can be added for more flavor.
- Make it dairy-free: Use dairy-free shredded cheese alternatives for both the mozzarella and Parmesan.

How to Make Spaghetti Squash Casserole:
- Preheat oven to 400°F. Carefully cut the spaghetti squash in half lengthwise and scoop out the seeds. Drizzle with olive oil and place cut-side down on a baking sheet. Roast for 35-40 minutes or until tender. Let cool slightly, then use a fork to scrape out the strands.
- In a large skillet over medium heat, sauté the diced onion until softened, about 5 minutes. Add garlic and cook for another minute. Add ground turkey and cook until browned and cooked through. Season with salt, black pepper, and Italian seasoning.
- Stir in the marinara sauce and bring to a simmer. Let cook for 5 minutes, then remove from heat.
- In a large mixing bowl, combine the roasted spaghetti squash strands with the turkey marinara mixture. Mix well and transfer to a greased 9x13" baking dish. Top evenly with mozzarella and parmesan.
- Reduce oven temperature to 375°F. Bake the casserole uncovered for 20-25 minutes, or until the cheese is melted and bubbly. Broil for 1-2 minutes at the end if desired for a golden top.
- Let cool slightly before serving. Garnish with fresh herbs, if desired.

Recipe Notes & Tips:
- Roast the squash cut-side down: This helps excess moisture evaporate so the casserole doesn't turn watery.
- Let the squash cool slightly: Allowing the spaghetti squash to cool before scraping helps release steam and keeps the strands from becoming mushy.
- Drain if needed: If the squash releases extra liquid after scraping, gently blot it with a paper towel before mixing.
- Season the turkey well: Don't skip seasoning the turkey as it cooks, this builds flavor throughout the casserole.
- Serving Suggestions: Serve this spaghetti squash casserole with sides like our Gluten-Free Focaccia or Wedge Salad for a balanced, weeknight-friendly meal.

How to Store:
Refrigerator: Let the casserole cool completely, then store leftovers in an airtight container in the fridge for up to 4 days.
Freezer: Freeze individual portions or the whole casserole (once cooled) in freezer-safe containers for up to 2 months. Thaw overnight in the fridge before reheating.
To Reheat: Warm in the oven at 350°F until heated through, or microwave individual portions in 30-second intervals until hot.
Spaghetti Squash Casserole FAQs:
To keep spaghetti squash casserole from being watery, roast the squash cut-side down, let it cool slightly before scraping, and blot any excess moisture from the strands if needed. Removing excess water before assembling the casserole helps the final dish stay thick and cohesive.
Yes. Spaghetti squash casserole is naturally gluten-free because spaghetti squash replaces traditional pasta and no wheat-based ingredients are used.
Spaghetti squash casserole can be frozen, but the texture may soften slightly after thawing. For best results, freeze it after baking and cooling completely, then thaw overnight in the refrigerator before reheating.


Grab your Free copy
Get a FREE Healthy Meal Planning Ebook

Spaghetti Squash Casserole
Equipment
Ingredients
- 2 medium spaghetti squash
- 1 pound ground turkey
- 1 cup onion, diced
- 3 garlic cloves, minced
- 24 ounces marinara sauce
- 1 teaspoon italian seasoning
- 1 cup shredded mozzarella cheese
- ½ cup grated parmesan cheese
Instructions
- Preheat oven to 400°F. Carefully cut the spaghetti squash in half lengthwise and scoop out the seeds. Drizzle with olive oil and place cut-side down on a baking sheet. Roast for 35-40 minutes or until tender. Let cool slightly, then use a fork to scrape out the strands.
- In a large skillet over medium heat, sauté the diced onion until softened, about 5 minutes. Add garlic and cook for another minute. Add ground turkey and cook until browned and cooked through. Season with salt, pepper, and Italian seasoning.
- Stir in the marinara sauce and bring to a simmer. Let cook for 5 minutes, then remove from heat.
- In a large mixing bowl, combine the roasted spaghetti squash strands with the turkey marinara mixture. Mix well and transfer to a greased 9x13" baking dish. Top evenly with mozzarella and parmesan.
- Reduce oven temperature to 375°F. Bake the casserole uncovered for 20-25 minutes, or until the cheese is melted and bubbly. Broil for 1-2 minutes at the end if desired for a golden top.
- Let cool slightly before serving. Garnish with fresh herbs, if desired.
Nutrition
Notes
- Roast the squash cut-side down: This helps excess moisture evaporate so the casserole doesn't turn watery.
- Let the squash cool slightly: Allowing the spaghetti squash to cool before scraping helps release steam and keeps the strands from becoming mushy.
- Drain if needed: If the squash releases extra liquid after scraping, gently blot it with a paper towel before mixing.
- Season the turkey well: Don't skip seasoning the turkey as it cooks, this builds flavor throughout the casserole.
- Serving Suggestions: Serve this spaghetti squash casserole with sides like our Gluten-Free Focaccia or Wedge Salad for a balanced, weeknight-friendly meal.





Loved this! Spaghetti squash is my favorite
yum!