Low-Carb Spaghetti Squash Lasagna (No Noodles!)

This spaghetti squash lasagna trades pasta noodles for tender roasted squash strands, but keeps the meaty, cheesy layers you love from a classic lasagna. It is hearty enough for a weeknight dinner and won’t leave you feeling heavy.

You’ll get ribbons of squash layered with a savory beef tomato sauce, creamy ricotta, and plenty of melted mozzarella. Most of the work happens in the oven, so you can pull it all together with about 20 minutes of hands-on time.

Why This One Hits the Spot

I keep coming back to this recipe because it delivers all the cozy baked-lasagna flavor without the post-meal slump. The spaghetti squash brings a faint natural sweetness and a tender bite, and it soaks up the sauce without turning into mush.

It is also forgiving. You can use ground turkey, toss in some wilted spinach, or swap the cheese blend based on what you have. Leftovers reheat surprisingly well and make a great lunch the next day.

Ingredients

• 1 large spaghetti squash (about 3 to 4 lb): look for one that feels heavy for its size
• 1 tbsp olive oil: for roasting
• 1 tsp fine sea salt: divided, or to taste
• ½ tsp black pepper: divided
• 1 lb ground beef: 85% lean works well; see variations for other proteins
• 1 small yellow onion, finely diced
• 3 cloves garlic, minced
• 2 cups marinara sauce: use your favorite jarred or homemade
• 1 tsp dried Italian seasoning
• 15 oz whole-milk ricotta cheese: full-fat gives the creamiest texture
• 1 large egg: helps the ricotta set during baking
• ½ cup grated Parmesan cheese
• 2 cups shredded low-moisture mozzarella: shred it from a block if you can; it melts smoother
• A handful of fresh basil leaves, for serving

Variations / Substitutions

• Ground turkey or chicken: Brown the same way, then drain well; the sauce stays lighter but still satisfying.
• Dairy-free option: Use a thick cashew ricotta and your favorite meltable vegan mozzarella; the egg can be replaced with 1 tablespoon flaxseed meal mixed with 2½ tablespoons water.
• Extra vegetables: Stir 3 to 4 cups of baby spinach into the hot meat sauce until wilted, or layer in sautéed sliced mushrooms.
• Fresh herbs: Swap the dried Italian seasoning with 2 teaspoons chopped fresh oregano and 1 tablespoon fresh parsley.
• More heat: A pinch of red pepper flakes in the meat sauce gives it a gentle kick.

If you enjoy layered veggie dishes, you might also like Eggplant Parmesan.

How to Make Spaghetti Squash Lasagna

Step 1: Roast the Squash

Preheat your oven to 400°F (200°C). Cut the spaghetti squash in half lengthwise and scoop out the seeds. Rub the cut sides with the 1 tbsp olive oil, then sprinkle with ½ tsp salt and ¼ tsp pepper. Place both halves cut-side down on a baking sheet and roast until a fork slides easily into the thickest part, 40 to 45 minutes.

The skin will look slightly blistered and the flesh will pull away in strands when you drag a fork across it. Let the squash cool just enough to handle, then use that fork to scrape all the golden strands into a bowl and set them aside.

Step 2: Brown the Meat Sauce

While the squash roasts, set a large skillet over medium-high heat. Add the ground beef and diced onion with the remaining ½ tsp salt and ¼ tsp pepper. Cook, breaking the meat into crumbles, until it loses its pink color and the onion softens, about 6 to 8 minutes. Drain off most of the fat.

Add the minced garlic and cook for 30 seconds, then stir in the 2 cups marinara sauce and 1 tsp Italian seasoning. Bring to a gentle simmer, reduce the heat to low, and let it bubble for 10 minutes. The sauce will thicken just a bit and smell deeply savory.

Step 3: Mix the Ricotta Filling

In a medium bowl, combine the 15 oz ricotta, 1 large egg, and the ½ cup grated Parmesan. Stir until the mixture is smooth and evenly blended. The egg will help the filling set into a creamy layer instead of running out when you cut into the lasagna.

Step 4: Layer the Casserole

Turn the oven down to 375°F (190°C). Spread a thin layer of the meat sauce (about ½ cup) across the bottom of a 9×13 inch baking dish. Scatter half of the spaghetti squash strands over the sauce and press them down lightly. Dollop half of the ricotta mixture over the squash, then add half of the remaining meat sauce and a sprinkle of mozzarella (about ¾ cup). Repeat with the remaining squash, ricotta, sauce, and finish with a generous blanket of the rest of the mozzarella.

The layers may look a bit rustic and that is exactly right. They will meld together in the oven.

Step 5: Bake and Broil the Lasagna

Bake the assembled casserole until the sauce is bubbling around the edges and the cheese is fully melted, 25 to 30 minutes. For a golden, spotty top, switch the oven to broil, move the dish to the upper rack, and broil for 2 to 3 minutes, keeping a close eye so it does not burn.

Let the lasagna rest for 5 minutes so the layers hold their shape, then tear over the fresh basil and serve it warm.

Tips for the Best Spaghetti Squash Lasagna

• After scraping the squash, let the strands sit in a colander for a few minutes and press gently with paper towels. Removing excess water prevents a soupy casserole.
• For extra richness, mix a handful of torn fresh basil right into the ricotta filling along with the Parmesan.
• If your baking dish is very full, place it on a foil-lined baking sheet to catch any drips.
• Assemble the whole dish (without baking) up to one day ahead. Cover and refrigerate, then add 10 minutes to the bake time and bake straight from the fridge.

Roasting times for spaghetti squash by size:

Storing Leftover Lasagna

• Refrigerate: Keep slices in an airtight container for up to 4 days. The flavors actually deepen overnight.
• Reheating: Warm individual portions in the microwave or cover the whole dish with foil and reheat in a 350°F oven for about 15 minutes until heated through.

What to Serve With Spaghetti Squash Lasagna

A crisp, lemony green salad cuts through the richness nicely. I like to toss arugula with a simple vinaigrette and a handful of shaved Parmesan. For something warm, garlicky sautéed broccolini or roasted green beans round out the plate without competing.

Frequently Asked Questions

Can I freeze this lasagna?

Yes. Bake and cool it completely, then freeze the whole dish or individual portions tightly wrapped for up to 2 months. Thaw overnight in the fridge before reheating.

My squash released a lot of water. What went wrong?

The roasting time might have been too short, or the squash was particularly large and moist. Next time, roast until the strands are visibly dry at the edges and let them drain before layering.

Can I skip the egg in the ricotta?

You can leave it out. The filling will be a little looser when you cut into the lasagna but still tastes great. Stirring the ricotta well helps it hold together.

What is the best way to cut a raw spaghetti squash?

Pierce the skin in a few places with a knife, microwave it whole for 3 minutes to soften the shell slightly, then halve it carefully with a large sharp knife on a stable surface.

Spaghetti Squash Lasagna Recipe

Print Recipe Pin Recipe

Prep Time 20 minutes mins

Cook Time 1 hour hr 15 minutes mins

Total Time 1 hour hr 35 minutes mins

Servings: 6 servings

Calories: 390

Ingredients Method Notes

Ingredients

  

• 1 large spaghetti squash (about 3 to 4 lb)
• 1 tbsp olive oil
• 1 tsp fine sea salt, divided
• ½ tsp black pepper, divided
• 1 lb ground beef
• 1 small yellow onion, finely diced
• 3 cloves garlic, minced
• 2 cups marinara sauce
• 1 tsp dried Italian seasoning
• 15 oz whole-milk ricotta cheese
• 1 large egg
• ½ cup grated Parmesan cheese
• 2 cups shredded low-moisture mozzarella
• A handful of fresh basil leaves, for serving

Method

 

1. Preheat oven to 400°F. Halve squash, remove seeds, rub with oil, season with ½ tsp salt and ¼ tsp pepper. Roast cut-side down 40 to 45 minutes until fork-tender, then scrape strands and set aside.
2. Brown beef and onion over medium-high heat with remaining salt and pepper until cooked, 6 to 8 minutes. Drain fat, add garlic, marinara, and Italian seasoning, and simmer 10 minutes.
3. Mix ricotta, egg, and Parmesan until smooth.
4. Lower oven to 375°F. Layer a 9×13 dish: thin meat sauce, half the squash, half the ricotta, half remaining sauce, and some mozzarella. Repeat layers and top with the rest of the mozzarella.
5. Bake 25 to 30 minutes until bubbly, then broil 2 to 3 minutes for a golden top. Rest 5 minutes, scatter basil, and serve.

Notes

If your squash strands feel wet after scraping, let them drain in a colander for a few minutes and blot with paper towels. This keeps the casserole from turning watery.