Sausage and Peppers Spaghetti Squash Casserole – Comfort Food, Lightened Up

There’s something about baked casseroles that instantly feels like home warm, cheesy, bubbling, and hearty. But what if you could enjoy all that comfort without the heavy carbs? Enter this Sausage and Peppers Spaghetti Squash Casserole a lighter, gluten-free twist on a classic Italian comfort dish that doesn’t sacrifice flavor.

It’s everything you crave in a baked pasta: layers of roasted spaghetti squash strands, savory sausage, sautéed bell peppers, and a rich tomato sauce all topped with gooey melted cheese. The flavors are bold and comforting, yet the dish feels lighter and more balanced thanks to the spaghetti squash base. Whether you’re looking for a wholesome weeknight dinner or a crowd-pleasing bake for the weekend, this casserole is hearty, delicious, and just as satisfying as the real thing.

What Is Sausage and Peppers Spaghetti Squash Casserole

This casserole combines roasted spaghetti squash “noodles” with Italian sausage, bell peppers, onions, marinara sauce, and melted cheese to create a rich, comforting dish that’s lower in carbs but big on flavor. Think of it as a cross between baked ziti and classic sausage and peppers with a twist of wholesome spaghetti squash taking the place of pasta. Each bite delivers the perfect mix of smoky sausage, sweet peppers, creamy cheese, and tangy tomato sauce. It’s a one-pan wonder that feels indulgent but nourishes you at the same time.

this Recipe

Why You’ll Fall in Love with This Recipe

This recipe has everything you want in a comfort meal: rich flavor, creamy cheese, and a satisfying texture yet it’s naturally gluten-free and packed with veggies. You’ll love how the roasted spaghetti squash strands soak up the sauce without turning soggy, and the sausage and peppers bring all the Italian-style flavor you crave. Plus, it’s a make-ahead hero — you can prepare it in advance, refrigerate it, and bake it when ready. It’s meal-prep friendly, family-approved, and perfect for cozy nights in.

How Does It Taste?

The flavor is pure Italian comfort. The spaghetti squash adds a tender, slightly sweet base that complements the savory, spicy sausage and the caramelized peppers and onions. The tomato sauce binds everything together, creating a luscious texture, while the bubbling melted mozzarella and Parmesan on top add that golden, cheesy finish. It’s hearty, meaty, and deeply flavorful the kind of dish that makes everyone go back for seconds.

Health & Ingredient Benefits

This casserole delivers indulgence without the guilt. Spaghetti squash is naturally low in calories and carbs while providing fiber, vitamins A and C, and antioxidants. Italian sausage adds protein and rich flavor you can use chicken or turkey sausage for a leaner version. Bell peppers are high in vitamin C and add color, sweetness, and crunch. The cheese provides calcium and richness, while using marinara sauce keeps it easy and full of lycopene from tomatoes. Altogether, it’s a nourishing, satisfying meal that fits a balanced lifestyle.

Ingredients You’ll Need

For the Squash Base:

• 1 large spaghetti squash (about 3 pounds)
• 1 tablespoon olive oil
• Salt and black pepper to taste

For the Filling:

• 1 pound Italian sausage (mild or spicy, casings removed)
• 1 tablespoon olive oil
• 1 small onion, diced
• 1 red bell pepper, diced
• 1 yellow bell pepper, diced
• 3 cloves garlic, minced
• 2 cups marinara sauce (store-bought or homemade)
• 1 teaspoon Italian seasoning
• ½ teaspoon crushed red pepper flakes (optional)
• Salt and black pepper, to taste

For Assembling:

• 1 ½ cups shredded mozzarella cheese
• ½ cup grated Parmesan cheese
• 2 tablespoons chopped fresh basil or parsley (for garnish)

Tools You’ll Need

• Baking sheet
• Sharp knife and spoon
• Large skillet
• Mixing bowl
• Casserole dish (9×13-inch)
• Spatula
• Aluminum foil

Optional Substitutions & Additions

• Protein swap: Use ground chicken, turkey, or even plant-based sausage.
• Cheese options: Add ricotta or cream cheese for a creamier casserole.
• Veggie boost: Add spinach, zucchini, or mushrooms to the filling.
• Spicy kick: Mix in crushed red pepper or use hot Italian sausage.
• Sauce twist: Try a creamy Alfredo sauce for a richer variation.

How to Make

1. Roast the squash: Preheat oven to 400°F (200°C). Slice spaghetti squash lengthwise, remove seeds, and brush the insides with olive oil. Season with salt and pepper. Place cut side down on a parchment-lined baking sheet and roast for 35–40 minutes, until tender. Let cool slightly, then scrape the flesh into strands with a fork.
2. Cook the sausage and vegetables: In a large skillet, heat olive oil over medium heat. Add sausage and cook until browned, breaking it apart with a spatula. Add diced onion and bell peppers, and sauté for 5–7 minutes until softened. Stir in garlic and cook another 30 seconds.
3. Combine with sauce: Add marinara sauce, Italian seasoning, and red pepper flakes. Simmer for 5 minutes to blend flavors. Taste and adjust seasoning.
4. Assemble the casserole: In a large mixing bowl, combine roasted spaghetti squash strands with the sausage-pepper mixture. Stir in 1 cup of mozzarella and half of the Parmesan. Transfer to a greased casserole dish.
5. Top and bake: Spread remaining mozzarella and Parmesan on top. Cover with foil and bake at 375°F (190°C) for 20 minutes. Uncover and bake an additional 10 minutes until bubbly and golden.
6. Serve: Let rest for 10 minutes before serving. Sprinkle with chopped basil or parsley for freshness.

What to Serve With

This casserole is a complete meal on its own, but it pairs beautifully with a crisp green salad or roasted vegetables. For a classic Italian touch, serve with garlic bread or a side of sautéed spinach. A glass of red wine Chianti or Merlot complements the rich flavors perfectly.

Why It’s Perfect for Busy Nights

This dish is ideal for busy weeknights or meal prep. You can roast the spaghetti squash and cook the sausage ahead of time, then assemble and bake when ready. It reheats beautifully and makes generous portions that store well for several days. It’s family-friendly, freezer-friendly, and budget-friendly all while feeling like something special.

Tips for Success

• Roast squash cut side down for the best caramelized flavor.
• Drain excess liquid from the squash before mixing to avoid sogginess.
• Use a flavorful marinara sauce — it’s the base of your dish.
• Shred your own cheese for the best melt and texture.
• Let the casserole rest before slicing for neat servings.

Common Mistakes to Avoid

• Undercooking squash: Make sure it’s tender enough to scrape easily.
• Overcooking veggies: Keep some bite in your peppers for texture.
• Skipping seasoning: Spaghetti squash needs flavor — taste and adjust salt.
• Watery casserole: Always drain squash before mixing.

How to Store & Reheat

Cool completely, then cover tightly and refrigerate for up to 4 days. Reheat in the oven at 350°F (175°C) for 10–15 minutes or microwave individual portions. To freeze, wrap tightly and store up to 2 months. Thaw overnight in the fridge before reheating.

Frequently Asked Questions

Can I make this ahead?
Yes, assemble up to a day ahead and refrigerate. Bake when ready to serve.

Can I use pre-cooked spaghetti squash?
Definitely — it saves time. Just make sure to drain excess moisture.

Can I make it dairy-free?
Yes! Use dairy-free mozzarella and nutritional yeast in place of Parmesan.

Can I add pasta instead of squash?
Sure! Substitute cooked spaghetti or penne for a traditional version.

Nutritional Info (approximate per serving)

Calories: 320 | Protein: 21g | Fat: 18g | Carbohydrates: 18g | Fiber: 4g | Sugars: 7g | Sodium: 480mg

Conclusion

This Sausage and Peppers Spaghetti Squash Casserole brings all the flavors of classic Italian comfort food without the heaviness. It’s rich, cheesy, and soul-warming, yet fresh and wholesome enough for everyday dinners. Whether you’re following a low-carb lifestyle, eating gluten-free, or just craving something cozy and flavorful, this casserole delivers every time. Serve it hot, bubbling, and golden and watch it disappear faster than you can say “seconds, please!”

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October 26, 2025 by Melissa