Spaghetti Squash Alfredo with Creamy Garlic Parmesan Sauce

Tender roasted squash strands tossed with a rich homemade Alfredo sauce make this Spaghetti Squash Alfredo a satisfying low carb and keto friendly recipe. It is creamy, comforting, and easy enough for a weeknight dinner, whether you serve it as a vegetarian main dish or a flavorful side.

2 halves of spaghetti squash alfredo on baking sheet, garnished with parsley

If you love creamy pasta but want a lighter, lower carb option, spaghetti squash is a delicious alternative. It will not taste exactly like traditional pasta, but when it is roasted until tender and paired with a smooth Parmesan Alfredo sauce, it becomes a cozy and flavorful dish in its own right. The squash has a naturally mild flavor and a strand-like texture that works beautifully with rich sauces.

This low carb Spaghetti Squash Alfredo is a great choice for anyone looking for a keto friendly dinner, a meatless meal, or a vegetable-forward side dish. The key is cooking the squash properly so the strands stay tender without turning mushy, then coating them in a warm, creamy sauce made with heavy cream, butter, garlic, and freshly grated Parmesan cheese.

spaghetti squash alfredo on plate with shaved parmesan

What’s in this Low Carb Spaghetti Squash Alfredo recipe?

This easy spaghetti squash with Alfredo sauce uses simple ingredients and a few pantry seasonings. The combination creates a creamy, savory sauce that clings to the roasted squash strands. You can find the exact measurements in the recipe card below.

Spaghetti squash – Choose a squash that weighs about 3 pounds. Once roasted, the flesh pulls apart into long, spaghetti-like strands.
Olive oil – Helps the squash roast evenly and adds a light richness.
Heavy whipping cream – Forms the base of the Alfredo sauce and gives it a thick, creamy texture.
Butter – Adds richness and helps create a smooth sauce. If using salted butter, taste before adding extra salt.
Garlic – Fresh minced garlic and garlic powder add savory flavor throughout the sauce.
Seasonings – Italian seasoning, salt, black pepper, and crushed red pepper flakes bring balance and a gentle kick.
Parmesan cheese – Freshly grated Parmesan melts into the sauce for the best texture and flavor.
Chopped parsley – Adds color and freshness just before serving.

Tips & Variations

These simple tips will help you make perfectly roasted spaghetti squash and a smooth, creamy Alfredo sauce every time. You can also adjust the recipe to suit your meal or taste preferences.

Don’t overcook the spaghetti squash. Roast the squash until it is fork tender, but avoid cooking it so long that the strands become watery or mushy. A slightly firm, al dente texture works best with Alfredo sauce.
Keep the sauce at a gentle simmer. Alfredo sauce should not boil. High heat can cause the cream to separate or curdle, so keep the temperature controlled.
Whisk constantly. Stirring keeps the sauce smooth and helps prevent it from sticking to the bottom of the pan or burning.
Use freshly grated Parmesan. Parmesan grated from a block melts more smoothly than pre-shredded cheese and gives the sauce a better texture.
Add protein if desired. Cooked chicken, shrimp, or bacon can be added for a heartier meal.
Try another sauce. If Alfredo is not your preference, roasted spaghetti squash also pairs well with a classic tomato-based sauce or marinara-style sauce.

half of a roasted spaghetti squash mixed with alfredo sauce, garnished with parsley

Serving Suggestions

Spaghetti Squash Alfredo is rich and satisfying enough to enjoy as a low carb vegetarian dinner. For a simple finish, top it with cracked black pepper, a little extra Parmesan, and chopped parsley. A small squeeze of lemon can also brighten the creamy sauce and balance the richness.

If you want a more filling meal, add cooked chicken, shrimp, or bacon before serving. A crisp side salad is also a nice contrast to the creamy Alfredo sauce. If you are not following a keto or low carb diet, garlic bread can be served alongside it for a classic comfort-food pairing.

How to Store & Reheat Leftovers

How long does spaghetti squash last? Cooked spaghetti squash can be stored in the refrigerator for up to 4 days.
How to store leftovers. Store the spaghetti squash and Alfredo sauce together or separately in airtight containers in the refrigerator for up to 4 days.
How to reheat leftovers. Reheat gently in the microwave or on the stovetop. Use low heat if reheating on the stove so the sauce stays creamy.

This creamy low carb Spaghetti Squash Alfredo is simple, comforting, and full of flavor. Serve it warm as a main dish or a side, and enjoy the combination of roasted squash and homemade Alfredo sauce.

Spaghetti Squash Alfredo

Prep: 20

Cook: 1

Total: 1 20

Servings: 6 to 8 servings

Perfectly roasted spaghetti squash and creamy homemade Alfredo sauce come together in this easy low carb, keto friendly recipe. Serve it as a comforting vegetarian main dish or a flavorful side.

Ingredients

3 pound spaghetti squash, cleaned and dried
1 tablespoon olive oil
1 & 1/2 cups heavy whipping cream
1/2 cup butter, cut into cubes
2 cloves garlic, minced
1/2 teaspoon garlic powder
1/2 teaspoon dried Italian seasoning
1/4 teaspoon coarse salt
1/4 teaspoon cracked black pepper
1/8 teaspoon crushed red pepper flakes
2 cups freshly grated Parmesan cheese
1 tablespoon chopped parsley, for garnish

Instructions

Roast the squash

Preheat the oven to 400 degrees F.
Cut the squash in half lengthwise. Scoop out the seeds with a spoon and discard them. Drizzle the cut sides with olive oil, then place the squash cut side down on a baking sheet. Bake for 1 hour, or until the squash is fork tender.
Use a fork to scrape the cooked squash into long spaghetti-like strands.
Transfer the squash strands to a large mixing bowl and keep them warm.

Make the Alfredo Sauce

In a large nonstick saucepan over medium-low heat, combine the heavy cream and butter. Whisk until the butter has melted. Add the minced garlic, garlic powder, Italian seasoning, salt, black pepper, and crushed red pepper flakes. Whisk until the sauce is smooth and well combined.
Increase the heat slightly and bring the mixture to a gentle simmer, but do not let it boil. Cook for 3 to 5 minutes, whisking constantly, until the sauce begins to thicken and reduce slightly. Stir in the freshly grated Parmesan cheese just until melted and smooth.
Remove the sauce from the heat and toss it with the cooked squash strands. If the sauce needs to thicken more, let it stand for 2 to 3 minutes before mixing with the squash.

Assemble the Spaghetti Squash Alfredo

Spoon the coated squash back into the empty squash halves.
Sprinkle with extra Parmesan and chopped parsley. Serve warm directly from the squash halves or divide onto plates.

Notes

For a heartier meal, add cooked chicken, shrimp, or bacon. If you prefer a different sauce, roasted spaghetti squash can also be served with a tomato-based spaghetti sauce or marinara-style sauce.

Nutrition

Nutritional information is an automatic calculation and may vary depending on the exact products used and any recipe changes. If these numbers are important to you, calculate them based on your specific ingredients.

More Alfredo Recipes:

Chicken Alfredo Pizza
Chicken Alfredo Lasagna Rolls
Homemade Alfredo Sauce
The best Chicken Alfredo
Chicken Alfredo Tortellini Soup
Chicken Alfredo Bake