Spaghetti Squash Lasagna with Italian Chicken Sausage Recipe

Spaghetti squash lasagna with hot Italian chicken sausage and a homemade spicy tomato sauce, topped with parmesan cheese and baked until the top is crispy

Spaghetti squash makes a great lighter alternative to traditional pasta. It won’t taste exactly like wheat noodles, but its tender strands create a satisfying texture that works beautifully in a lasagna-style bake. This recipe layers roasted spaghetti squash with a robust, spicy tomato and Italian chicken sausage sauce, binds everything with eggs, and finishes with a crisp, golden Parmesan topping.

This spaghetti squash lasagna is ideal if you want a filling, lower-calorie dinner or a meal-prep option. One large serving—about one-quarter of the pan—comes in around 326 calories, with a good amount of protein and fiber. The prep is straightforward: roast the squash, make the sauce, mix and bake. Most of the time is hands-off, making it convenient for busy days.

How to make Spaghetti Squash Lasagna

To roast the squash, poke holes in the skin with a small sharp knife and bake whole on the middle oven rack at 375°F (190°C) for about 1 hour and 20 minutes. If you prefer, cut the squash in half lengthwise, remove seeds, place cut-side down on a parchment-lined sheet, and roast for roughly 50 minutes. Let the squash cool for 5–10 minutes before cutting open. Scrape out seeds and the spongy inner bits, then use a fork to release the spaghetti-like strands.

Add the scraped strands directly to a greased 9×9 baking dish. Beat three eggs with a generous grind of black pepper and a pinch of sea salt, then pour the eggs over the squash and stir gently; the eggs help bind the strands so the finished lasagna holds together when sliced.

While the squash roasts, prepare the sauce. In a large skillet, sauté the ground spicy Italian chicken sausage with chopped onion and minced garlic until the sausage is fully cooked and the onion is soft. Add dried Italian seasoning and crushed red pepper flakes for heat, then pour in a can of fire-roasted crushed tomatoes. Simmer the sauce on medium-low for 10–15 minutes to meld flavors and thicken slightly. Taste and adjust salt and pepper as needed.

Stir the tomato and sausage sauce into the egg-coated squash strands in the baking dish, then sprinkle the top with Parmesan cheese. For a dairy-free option, swap Parmesan for nutritional yeast. Bake the assembled lasagna at 375°F (190°C) for about 40 minutes, until the top is set, golden and slightly crisped.

When it comes out of the oven your kitchen will smell amazing. Let the dish rest for 5–10 minutes to firm up before serving so slices hold their shape. Enjoy hot as a satisfying, lower-carb alternate to traditional lasagna.

Ingredients

1 large spaghetti squash (about 3–3½ pounds)

For the Sauce

½ pound ground spicy Italian chicken sausage
1 onion, chopped
4 cloves garlic, minced
1 teaspoon dried Italian seasoning
½ teaspoon crushed red pepper flakes (or ¼ tsp cayenne)
28 oz can fire-roasted crushed tomatoes
Salt and pepper to taste (about ½ tsp each)

For the Lasagna Assembly

3 eggs, beaten
3 tablespoons Parmesan cheese (or 2 tbsp nutritional yeast for dairy-free)

Instructions

Place whole spaghetti squash in the oven and bake at 375°F for 1 hour 20 minutes, or cut in half and bake cut-side down on a sheet for about 50 minutes, until the strands are tender but not mushy.
Remove squash and let rest 5–10 minutes. Cut open (if whole), drain any liquid, remove seeds and inner membranes, then use a fork to scrape out spaghetti-like strands. Add strands to a greased 9×9 baking dish.
While the squash cooks, make the sauce: sauté sausage, onion and garlic in a skillet until the sausage is no longer pink and the onion is soft. Stir in Italian seasoning, crushed red pepper, salt and pepper. Add crushed tomatoes and simmer 10–15 minutes to thicken.
Mix beaten eggs into the squash strands in the baking dish, then stir in the tomato-sausage sauce. Sprinkle with Parmesan or nutritional yeast.
Bake at 375°F for 40 minutes, until the top is browned and slightly crisp. Let rest 5–10 minutes before slicing and serving.

Tips, Variations & Storage

Make the tomato sauce in advance and refrigerate or freeze; it speeds assembly on busy days.
Swap chicken sausage for turkey or pork sausage, or use a plant-based crumbled sausage for a vegetarian-friendly option with a tomato-based protein substitute.
For extra vegetables, stir diced bell pepper, mushrooms or spinach into the sauce while it simmers.
Store leftovers in an airtight container in the refrigerator for 3–4 days, or freeze portions for up to 2 months. Reheat in the oven or microwave until warmed through.

Nutrition (per serving)

If you try this spaghetti squash lasagna, enjoy experimenting with spices and additions to match your taste. It’s a flavorful, comfort-food style meal that’s also well suited for meal prep and lighter eating plans.