Cheesy Low-Carb Spaghetti Squash Lasagna Recipe

This recipe is a lighter, low-carb take on classic lasagna. If you’ve enjoyed dishes like skillet lasagna or zucchini lasagna, you’ll appreciate how well spaghetti squash stands in for noodles. After roasting, the squash shreds into delicate strands that carry the creamy ricotta mixture and pair beautifully with a savory sausage marinara. The result is cheesy, satisfying, and perfect for cooler months.

One of the best parts: you don’t need a casserole dish. The squash halves act as individual lasagna boats, which makes assembly, serving, and cleanup easy.

Recipe ingredients

This recipe is easy to adapt to personal tastes and available ingredients.

• Spaghetti squash: 2 small to medium (about 1 1/2–2 lbs each). Roast and shred prior to assembling.
• Olive oil: 2 tablespoons, divided.
• Italian sausage: 16 ounces, casings removed. Substitute turkey sausage, ground meat, or 16 ounces chopped mushrooms for a vegetarian option.
• Onion and garlic: 1 onion (chopped) and 3 cloves garlic (minced) to flavor the marinara.
• Marinara sauce: About 2 cups—use your preferred store-bought sauce or a homemade tomato-basil marinara.
• Ricotta cheese: 1 cup (substitute cottage cheese if desired).
• Egg: 1 large egg to stabilize the ricotta mixture.
• Grated Parmesan: 1/3 cup to add savory depth to the filling.
• Fresh basil: 1/4 cup, chopped, plus extra for garnish (or 1 teaspoon dried basil in a pinch).
• Mozzarella: 2 cups grated for the topping—freshly grated melts best.

See the recipe card below for structured ingredient amounts, servings, and timing.

How to make lasagna with spaghetti squash

Making lasagna with spaghetti squash is straightforward. The process breaks down into three parts: preparing and roasting the squash, making the sausage marinara and ricotta filling, then stuffing and baking the squash halves. Prep the squash up to two days ahead to speed weeknight assembly.

Pro tip: Roast and shred the squash 1–2 days in advance. You can also assemble the boats a day ahead and bake when ready.

How to cut a spaghetti squash

1. Lay the squash horizontally and remove the stem with a sharp knife.
2. Stand the squash on one cut end and carefully slice it in half lengthwise. Use a large knife with a stable surface and caution if the squash is tall.
3. Scoop out seeds and the stringy center with a spoon.

Roast spaghetti squash

1. Preheat oven to 400°F (205°C). Brush the squash cut sides with 1 tablespoon olive oil and season with salt and pepper.
2. Place cut-side down on a rimmed baking sheet and roast 40–45 minutes, or until tender when pierced with a fork.
3. Allow to cool slightly, then shred the flesh into strands with a fork. You should have roughly 3 cups shredded squash total.

Assemble and bake

1. In a large skillet over medium heat, cook the Italian sausage until browned and cooked through, about 5 minutes. Remove with a slotted spoon and drain all but 1 tablespoon of fat.
2. Add the chopped onion to the skillet and sauté 4–5 minutes until softened. Stir in the minced garlic and cook 30 seconds, then return the cooked sausage to the pan and pour in the marinara. Simmer 5–8 minutes and remove from heat.
3. In a medium bowl, mix ricotta with the egg, grated parmesan, and chopped basil. Fold in the shredded spaghetti squash until combined.
4. Divide the ricotta-squash mixture among the four roasted squash halves. Spoon the sausage marinara over each and top with grated mozzarella.
5. Bake at 400°F for 10–15 minutes, until the cheese is melted and bubbly. For a browned top, broil 1–2 minutes while watching closely.
6. Garnish with additional chopped basil if desired and serve warm.

Yes. Spaghetti squash contains significantly fewer carbohydrates than traditional pasta, making it a popular lower-carb alternative.

Spaghetti squash provides fiber, potassium, and vitamins such as A, C and K, making it a nutritious choice in place of pasta.

Spaghetti squash has a mild, slightly sweet, and earthy flavor that pairs well with strong sauces and cheeses.

Yes. Cottage cheese can replace ricotta for added protein and a slightly different texture.