Spaghetti Squash Lasagna Recipe: Low-Carb, Gluten-Free

You will enjoy this vegetable-packed, low-carb friendly Spaghetti Squash Lasagna. It combines layers of ricotta and mozzarella with savory marinara, herbs, and a mix of vegetables for balanced flavor in every bite. Baked spaghetti squash replaces traditional pasta, so the casserole feels lighter while still delivering the comforting texture and taste of lasagna.

Reasons To Love Spaghetti Squash Lasagna

• Simple to prepare. Once the spaghetti squash is roasted and the ground beef is cooked, assemble the mixture, top with cheese, and bake—no boiling sheets of pasta required.
• Perfect for sharing. This lasagna is ideal for serving a small group or bringing to a potluck because it holds together well and appeals to many tastes.
• Vegetable-forward and customizable. The recipe is loaded with veggies and is easy to adapt—swap in zucchini, peppers, or extra greens to suit your preferences.

Ingredient Notes

Full ingredient amounts and the complete recipe are listed in the recipe card below.

• Spaghetti squash. This is the base for the dish. When roasted, its strands act like pasta and help keep the casserole low in net carbs.
• Ground beef. Using lean ground beef provides protein and savory depth. Ground turkey is an easy lean swap if you prefer.
• Vegetables. The recipe uses spinach, onions, and mushrooms, but you can add or substitute bell peppers, zucchini, or other veggies you like.
• Ricotta cheese. Full-fat ricotta gives the filling a creamy, rich texture and helps bind the squash and other ingredients together.
• Egg. A single egg helps hold the filling together so slices keep their shape after baking.
• Seasonings. Classic Italian flavors—dried basil, oregano, garlic, salt, and optional red pepper flakes—are used to build a well-rounded profile.
• Marinara. Use a quality marinara or tomato sauce to add moisture and acidity that balances the cheeses.
• Cheeses. Shredded mozzarella melts into a gooey top layer while grated parmesan adds an umami finish and garnish.

Steps To Make Squash Lasagna

Below is an overview of the process. Detailed measurements and a step-by-step recipe are available in the recipe card further down.

• Step One — Roast the spaghetti squash: Preheat the oven to 425°F (220°C). Pierce the squash several times with a fork and place it on a lined baking sheet. Roast until the skin is easily pierced with a knife and the flesh pulls into strands, about 45 minutes, turning once or twice for even cooking.
• Step Two — Prepare the squash flesh: Let the roasted squash cool briefly, then halve it and remove the seeds. Use a fork to separate the strands and transfer them to a large bowl.
• Step Three — Cook the meat and aromatics: While the squash roasts, sauté diced onions and garlic, then brown the ground beef until cooked through. Drain any excess fat if needed and combine with the squash.
• Step Four — Combine the filling: In the bowl with squash and beef, stir in ricotta, the egg, marinara, spinach, mushrooms, and seasonings until evenly mixed.
• Step Five — Assemble and bake: Spread the mixture into a greased 8×10 baking dish, top with shredded mozzarella and grated parmesan, cover with foil, and bake until heated through—about 1 hour. Remove the foil toward the end of baking to brown and bubble the cheese.
• Step Six — Rest and serve: Allow the lasagna to rest about 10 minutes after baking so it firms up, then slice and garnish with extra parmesan and chopped parsley before serving.

What To Serve With Spaghetti Squash Lasagna

This casserole is satisfying on its own, but it pairs beautifully with simple vegetable sides for a complete meal. Consider roasted or steamed vegetables, a crisp green salad, or a light side of roasted root vegetables to add contrast and color.

Recipe Tips

• Roast the spaghetti squash fully. It should be tender enough to pull into strands easily and cut without resistance.
• Prep ahead. Roast the squash the day before to save time on the day you plan to bake the lasagna.
• Customize the vegetables. Use any combination of vegetables you enjoy—zucchini, bell peppers, or extra leafy greens work well.
• Let it rest before slicing. Allowing the dish to cool for several minutes helps the layers set and makes serving cleaner slices.
• Storage. Store leftovers in an airtight container in the refrigerator for up to four days, or freeze portions for up to two months.

Spaghetti Squash Lasagna

By
Bailey Rhatigan

A light, vegetable-forward take on classic lasagna using roasted spaghetti squash, ricotta, marinara, and melted mozzarella for a comforting, lower-carb casserole.

Prep: 45 mins |
Total: 1 hr 45 mins |
Servings: 6

Equipment

• 8×10 baking dish (or similar)
• Baking sheet
• Large mixing bowl

Ingredients

• 1 large spaghetti squash (about 3–4 lbs)
• 1 lb lean ground beef
• 1/2 cup diced onions
• 2 cups chopped mushrooms
• 3 cloves garlic, minced
• 1 tsp dried basil
• 1 tsp dried oregano
• 1 tsp salt, or to taste
• 1 tsp red pepper flakes (optional)
• 1 cup full-fat ricotta
• 1 large egg
• 2 cups baby spinach, chopped
• 1 1/3 cup marinara or pasta sauce
• 1 1/2 cup shredded mozzarella
• 1 cup grated parmesan (reserve some for garnish)
• Fresh parsley, chopped, for garnish

Instructions

1. Roast the spaghetti squash. Preheat the oven to 425°F. Line a baking sheet with foil or parchment. Pierce the squash several times, place it on the sheet, and roast about 45 minutes, flipping halfway, until a knife slides into the skin easily.
2. Remove from the oven and let cool enough to handle. Halve the squash, scoop out the seeds, and use a fork to separate the strands into a large bowl.
3. Cook the beef and aromatics. While the squash roasts, finely chop the onion and mince the garlic. In a skillet over medium-high heat, brown the ground beef with onion and garlic until cooked through. Add the cooked beef to the bowl with the squash.
4. Combine filling ingredients. Add ricotta, half the parmesan, marinara, egg, spinach, mushrooms, basil, oregano, salt, and red pepper flakes. Mix until well combined.
5. Assemble the lasagna. Spray an 8×10 baking dish with cooking spray and spread the squash-beef mixture evenly. Top with shredded mozzarella and remaining parmesan. Cover loosely with foil.
6. Bake. Bake at 425°F for about 1 hour. Remove foil during the last 20 minutes to allow the cheese to brown and bubble. Let rest about 10 minutes before slicing. Garnish with extra parmesan and chopped parsley.

Notes

• Be sure the spaghetti squash is fully roasted; it should be tender and easy to shred with a fork.
• You can roast the squash in advance to streamline assembly on bake day.
• Substitute or add vegetables as desired—zucchini, bell peppers, or extra mushrooms are all good options.
• Leftovers keep in the refrigerator up to four days or can be frozen for up to two months.

Nutrition

Serving: 1 cup of lasagna • Calories: 469 kcal • Carbohydrates: 25 g • Protein: 36 g • Fat: 26 g • Sodium: 1250 mg

Nutrition information is an estimate and should be used as a guide.

Additional Info

Course: Main Course • Cuisine: American • Servings: 6 • Prep Time: 45 minutes • Total Time: 1 hour 45 minutes

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