Name: Spaghetti Squash Lasagna
Prep time: 20 min
Cook time: 1 h 15 min
Total time: 1 h 30 min
Cuisine: Italian-Inspired
Ingredients: 1 large spaghetti squash (about 3 ½ pounds); 2 teaspoons olive oil; 1 teaspoon olive oil; 1 medium onion, chopped; 3 cloves garlic, finely chopped; 1 can (28 oz) crushed tomatoes; 2 teaspoons dried Italian seasoning; 1/4 teaspoon red pepper flakes; 1/2 teaspoon black pepper; 1/2 teaspoon salt; 1 container (15 oz) part-skim ricotta cheese; 1 large egg; 5 ounces baby spinach (steamed and chopped, or thawed frozen spinach squeezed dry); 1/2 cup shredded part-skim mozzarella cheese; 1 teaspoon salt; 1/4 teaspoon black pepper; 1 1/2 cups shredded part-skim mozzarella cheese (remaining); 1/3 cup grated Parmigiano-Reggiano cheese; Chopped fresh parsley (optional, for garnish)

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This spaghetti squash lasagna is a lighter, more nutritious twist on the classic Italian comfort food. Instead of pasta, I use tender strands of roasted spaghetti squash layered with creamy ricotta, spinach, and a rich tomato sauce. The result is cheesy, satisfying, and packed with nutrients—all while being lower in calories than traditional lasagna.

Why You’ll Love This Recipe

I like this recipe because it gives me all the flavors of lasagna without the heaviness. The spaghetti squash makes it naturally gluten-free, and it adds extra fiber and vitamins. I also appreciate how versatile and make-ahead friendly it is—I can prepare it in advance, freeze it, or reheat leftovers during a busy week. It’s filling, comforting, and perfect for family dinners or potlucks.

Ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

1 large spaghetti squash (about 3 ½ pounds)
3 teaspoons olive oil, divided
1 medium onion, chopped
3 cloves garlic, finely chopped
1 can (28 oz) crushed tomatoes
2 teaspoons dried Italian seasoning
1/4 teaspoon red pepper flakes
1 1/2 teaspoons salt, divided
1/2 teaspoon black pepper, divided
1 container (15 oz) part-skim ricotta cheese
1 large egg
5 ounces baby spinach, steamed and chopped (or use thawed frozen spinach, squeezed dry)
1 1/2 cups shredded part-skim mozzarella cheese
1/3 cup grated Parmigiano-Reggiano cheese
Chopped parsley for garnish (optional)

Directions

I preheat the oven to 425°F (220°C). I cut the spaghetti squash in half lengthwise, scoop out the seeds, brush with 2 teaspoons olive oil, and place cut side down on a parchment-lined baking sheet. I roast until tender, about 40 minutes. Once cool, I scrape the flesh into spaghetti-like strands, yielding about 6 cups.
While the squash cooks, I make the sauce. In a large sauté pan, I heat 1 teaspoon olive oil over medium heat. I add onion and garlic, cooking for 4–5 minutes until softened. I stir in crushed tomatoes, Italian seasoning, red pepper flakes, 1/2 teaspoon salt, and 1/4 teaspoon pepper. I let it simmer 15–20 minutes until thickened.
In a large bowl, I mix ricotta, egg, spinach, 1/2 cup mozzarella, 1 teaspoon salt, and 1/4 teaspoon pepper. I squeeze out excess liquid from the squash and stir it into the ricotta mixture.
I reduce the oven temperature to 375°F (190°C). In an 8×11-inch baking dish, I spread 1 1/2 cups of sauce on the bottom. I layer the squash mixture evenly over it, then top with remaining sauce. I finish with the rest of the mozzarella and the Parmigiano-Reggiano.
I bake for 35–40 minutes, until bubbly and golden. I let it rest for 10 minutes before slicing and serving, garnished with parsley.

Servings and timing

This recipe makes about 8 servings. It takes me 20 minutes to prepare, 40 minutes to roast the squash, and 35–40 minutes to bake—so I allow about 1 hour and 30 minutes total. Each serving is around 244 calories, with 16 grams of protein and 4 grams of fiber.

Variations

Sometimes I add ground turkey or chicken to the tomato sauce for extra protein. For a spicier kick, I use hot Italian seasoning or add more red pepper flakes. If I want it extra cheesy, I mix some mozzarella directly into the squash and ricotta layer. I’ve also swapped spinach for kale or used roasted vegetables like mushrooms and zucchini in place of some of the squash.

storage/reheating

I store leftovers in an airtight container in the fridge for up to 4 days. To reheat, I warm portions in the oven at 350°F until heated through, which keeps the texture intact. The microwave works for quicker reheating, though the layers can soften more. This lasagna also freezes well—after cooling, I wrap it tightly in plastic wrap and foil and freeze for up to 3 months. I bake it straight from frozen at 375°F until hot and bubbly.

FAQs

Can I cook the spaghetti squash in the microwave?

Yes, I pierce it several times with a knife, microwave it whole for 10–12 minutes, then cut it open and scrape out the strands.

Can I use jarred marinara sauce?

Yes, I often use my favorite store-bought sauce when I want to save time.

Can I make this ahead of time?

Yes, I assemble the lasagna, cover it, and refrigerate for up to 24 hours before baking.

Can I use frozen spinach instead of fresh?

Yes, I thaw it, squeeze out the liquid, and mix it right in with the ricotta.

How do I keep the lasagna from getting watery?

I always squeeze the roasted squash really well to remove excess liquid. This helps the layers hold together.

Conclusion

This spaghetti squash lasagna is one of my favorite lighter comfort meals. I love how it captures the flavors of traditional lasagna while being more nutritious and easier on the stomach. It’s hearty, cheesy, and satisfying—perfect for busy nights, potlucks, or when I want a wholesome dish that still feels indulgent.

Spaghetti Squash Lasagna