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Spaghetti Squash Lasagna is serious low-carb comfort food, and you definitely won’t miss the carbs in this tasty lasagna casserole! We used spicy Italian sausage and three kinds of cheese in this for lots of great lasagna flavors.

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Mock Lasagna Spaghetti Squash Casserole with one serving on plate with fork and baking dish in back

Spaghetti Squash Lasagna is a low-carb dinner idea that really knocked our socks off when we tested it! Have you heard of the idea of making lasagna with spaghetti squash replacing the noodles? I promise it’s absolutely a thing, and this is so delicious!

In this mock lasagna casserole the traditional lasagna ingredients are layered with cooked spaghetti squash. And this has the same flavors that make regular lasagna with pasta such a popular dish! If you like those flavors and you’re looking for dinner ideas, I promise this will be a winner!

And of course this is much lower in carbs than traditional lasagna. I love this lasagna casserole and it’s perfect for fall, so I’m featuring it as my Friday Favorites pick this week.

What ingredients do you need?

(This is only a list of ingredients; please scroll down for complete printable recipe. Or if you use the JUMP TO RECIPE link at the top of the page, it will take you directly to the complete recipe with ingredient amounts.)

What marina sauce did I use for Spaghetti Squash Lasagna?

I’m a huge fan of Rao’s Pasta Sauce (affiliate link) which is really low in carbs, and I’d use one of their sauces for this recipe if I didn’t have any of my Sausage and Basil Marinara Sauce in the freezer. Any low-sugar or purchased sauce will work for this recipe.

Ideas for cooking spaghetti squash to make it into Lasagna:

I’m a fan of roasting the spaghetti squash for a recipe like this, because it dries it out a bit. But if you want another method for cooking the spaghetti squash, you can cook spaghetti squash in a crockpot or an Instant Pot for this recipe.

How low in carbs is this tasty Spaghetti Squash Lasagna?

For everyone who loves lasagna but doesn’t want the carbs, this tasty lasagna with spaghetti squash replacing the noodles has only 9.2 net carbs per serving and 34 grams of protein!

recipe steps collage for Mock Lasagna Spaghetti Squash Casserole

How to make Spaghetti Squash Lasagna:

(This is only a summary of the steps for the recipe; please scroll down for complete printable recipe. Or if you use the JUMP TO RECIPE link at the top of the page, it will take you directly to the complete recipe.)

  1. I roasted two spaghetti squashes for this, but if you have one large one (about 4 pounds), it will be plenty for the casserole. Microwave the squash about 5 minutes to soften, cut the spaghetti squash in half, scrape out seeds, rub with olive oil and Italian herb blend, and roast 50-60 minutes. (Or cook the spaghetti squash in a crockpot or an Instant Pot if you prefer, but I think roasting does add flavor.)
  2. While the squash cooks, squeeze the turkey sausage out of the casings and brown well. 
  3. Add the marinara sauce, dried basil, Italian herb blend, and garlic powder and simmer until the liquid is mostly evaporated, about 30 minutes. 
  4. Mix together the cottage cheese, eggs, and Italian Herb blend.
  5. Make a layer of half the spaghetti squash in an 8 inch x 11 inch casserole dish.
  6. Top with half the sauce, half the cottage cheese mixture, and half the cheese.
  7. Then make another layer of spaghetti squash, sauce, cottage cheese mixture, and the rest of the cheese.
  8. Bake uncovered at 375F/190C for about 45 minutes.  (Mine got a little brown on the edges, but that didn’t bother us a bit.)
  9. Serve the Spaghetti Squash Lasagna hot and devour!

Make it a Low-Carb Meal:

This tasty lasagna casserole would taste great with any of these low-carb side salads:

Mock Lasagna Spaghetti Squash Casserole with baking dish and one plate of spaghetti squash lasagna

More Tasty Options for Low-Carb Lasagna:

Check out Best Keto Lasagna Recipes for even more tasty dinners with lasagna flavors!

Weekend Food Prep:

Spaghetti Squash Lasagna has been added to a category called Weekend Food Prep where you’ll find recipes you can prep or cook on the weekend and eat during the week!

Mock Lasagna Spaghetti Squash Casserole finished dish with one serving on plate
Yield: 8 servings

Spaghetti Squash Lasagna

Prep Time 1 hour 15 minutes
Cook Time 45 minutes
Total Time 2 hours

This Spaghetti Squash Lasagna is serious comfort food, and you won’t miss the carbs in this tasty lasagna casserole made with spaghetti squash.

Ingredients

Spaghetti Squash Ingredients:

  • 1 large spaghetti squash, about 4 pounds
  • 2 tsp. olive oil (for brushing squash)
  • 2 tsp. Italian Herb Blend (for sprinkling on squash before roasting)

Sauce Ingredients:

  • 2 tsp. olive oil
  • 19.5 oz. pkg. hot turkey (or pork) Italian Sausage
  • 3 cups marinara sauce (see notes)
  • 1 tsp. dried basil
  • 1 tsp. Italian Herb Blend
  • 1 tsp. garlic powder (or use minced fresh garlic if you prefer)

Casserole Ingredients:

  • 2 cups cottage cheese
  • 2 eggs
  • 1 tsp. Italian Herb Blend
  • 2 cups grated Mozzarella
  • 1/2 cup coarsely grated Parmesan cheese

Instructions

  • Preheat oven to 400F/200C.
  • If desired, microwave the spaghetti squash for about 5 minutes (to soften the skin so it’s easier to cut.)  Cut squash in half lengthwise and scrape out the seeds.  Brush the inside of each half with olive oil and sprinkle with Italian Herb Blend.
  • Roast the squash on a flat baking sheet about 50-60 minutes, or until the squash strings apart easily with a fork.  (You can also cook the spaghetti squash in a crockpot or an Instant Pot for this recipe.)
  • While the squash cooks,  heat the olive oil in a large non-stick frying pan, squeeze the sausage out of the casings, and brown sausage well, breaking it apart with a turner while it cooks. (I like to use an old-fashioned Potato Masher (affiliate link) to break the sausage apart.)
  • When the sausage is well-browned, add the 3 cups of sauce, dried basil, Italian Herb Blend, and garlic powder, and simmer on low until most of the liquid has evaporated, about 30 minutes.
  • Put the cottage cheese into a bowl, add the eggs and Italian Herb Blend, and mix with a fork until the egg is well-mixed into the cottage cheese.
  • Prepare grated Mozzarella and coarsely grated Parmesan.
  • Spray an 8 inch by 11 inch casserole dish with non-stick spray.
  • When the spaghetti squash is done, turn oven heat down to 375F/190C and let squash cool for a few minutes.  Then use a fork to scrape the squash away from the skin, separating it into strands of “spaghetti.”  Discard the skin.
  • In the casserole dish, layer half the spaghetti squash, half the reduced sauce mixture, half the cottage cheese mixture, half the Mozzarella, and half the Parmesan.
  • Repeat with another layer each of squash, sauce, cottage cheese mixture, Mozzarella, and Parmesan.
  • Bake uncovered until the casserole is bubbling hot and the cheese is melted and lightly browned, about 40-45 minutes.
  • Serve Spaghetti Squash Lasagna hot, with additional Parmesan cheese to add at the table if desired.

    • Notes

    Use a 24 oz. of marinara sauce, either homemade or from a jar. For purchased sauce I recommend Rao's Pasta Sauce (affiliate link) which has only 20 carbs in the whole bottle.

    Recipe created by Kalyn.

    Nutrition Information

    Yield

    8

    Serving Size

    1
    Amount Per Serving Calories 421Total Fat 23gSaturated Fat 8gUnsaturated Fat 11gCholesterol 149mgSodium 1419mgCarbohydrates 13.2gFiber 4gSugar 10gProtein 34g

    Nutrition information is automatically calculated by the Recipe Plug-In I am using. I am not a nutritionist and cannot guarantee 100% accuracy, since many variables affect those calculations.

    Did you make this recipe?

    Did you make this recipe? Please leave a star rating (under the PRINT button in the recipe) or share a photo of your results on Instagram! THANKS!

    © Kalyn Denny
    Category: Casseroles

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    Low-Carb Diet / Low-Glycemic Diet / South Beach Diet Suggestions:
    This Spaghetti Squash Lasagna recipe is great for low-carb and Keto diets and it’s also gluten-free. If you’re making this for the original South Beach Diet, they would recommend using low-fat cottage cheese and low-fat Mozzarella (as well as low-fat turkey Italian sausage.) For other types of low-carb diets, use the dairy products and sausage you prefer.

    Find More Recipes Like This One:
    Use Spaghetti Squash or Casseroles to find more recipes like this one. Use the Diet Type Index to find recipes suitable for a specific eating plan. You might also like to follow Kalyn’s Kitchen on Pinterest, on Facebook, on Instagram, on TikTok, or on YouTube to see all the good recipes I’m sharing there.

    Historical Notes for this Recipe:
    This recipe for a lasagna casserole made with spaghetti squash was first posted in 2015, and it’s been popular on the website ever since. It was last updated with more information in 2025.

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