If you're missing creamy pasta dishes on keto, this keto spaghetti squash Alfredo casserole is going to hit the spot. Tender strands of spaghetti squash are tossed with a rich homemade Alfredo sauce, topped with plenty of mozzarella and Parmesan cheese, then baked until hot, bubbly, and golden.
It's an easy low-carb, gluten-free alternative to a traditional Alfredo pasta bake, and the mild flavor of spaghetti squash allows that creamy Parmesan sauce to really shine.
I especially love serving this spaghetti squash Alfredo as a side dish with roasted chicken, beef, pork, or ham.
You can also pair it with a simple green salad and enjoy it as a lighter meatless meal.
Be sure to check out our entire collection of keto casseroles for even more family-friendly low-carb recipes.
Why You'll Love This Keto Spaghetti Squash Alfredo Casserole
There is a lot to love about this easy low-carb casserole. It combines simple ingredients with a homemade Alfredo sauce for a dish that feels rich and satisfying without traditional pasta.
The spaghetti squash gives you those familiar noodle-like strands, while heavy cream, cream cheese, butter, and Parmesan create a smooth, creamy sauce.
A generous mozzarella and Parmesan topping makes it extra cheesy before the casserole is baked until golden.
It's also naturally gluten-free and works beautifully as either a side dish or a light meal.
What Is Spaghetti Squash?
Spaghetti squash is a winter squash that forms long, thin strands after it is cooked. Simply scrape the cooked flesh with a fork and it separates into strands that resemble spaghetti noodles.
Unlike zucchini noodles, which can release quite a bit of water while cooking, spaghetti squash has a slightly firmer texture that works especially well in baked low-carb casseroles.
Is Spaghetti Squash Keto?
Wondering how many carbs are in spaghetti squash and if it's keto-friendly?
You'll be happy to know that spaghetti squash is indeed low in carbs and can fit your keto macros since it clocks in at a total carbs 7.6 and 5.6 net carbs per one-cup serving.
Compared to regular pasta Alfredo which has upwards of 39.5 net carbs; it's a good pasta alternative dish for anyone watching their carbs.
Ingredients Needed For This keto Spaghetti Squash Casserole
Note that the full printable recipe card is at the bottom of the page.
Not only is this a yummy recipe, but it's super easy. With only a few basic ingredients, you can enjoy a meal that makes you feel like you are cheating on keto.
Using spaghetti squash as a pasta impersonator is pure genius. I can't wait for you to see how simple it is to make keto a delicious breeze.
Spaghetti Squash Alfredo
- Large spaghetti squash
- Unsalted butter
- Heavy cream
- Softened cream cheese
- Sea salt
- Garlic powder
- Onion powder
- Nutmeg powder, just a pinch
- Freshly cracked black pepper
- Shredded Parmesan cheese
Cheese Topping
- Shredded mozzarella cheese
- Shredded Parmesan cheese
How To Make This Keto spaghetti squash alfredo Casserole
To start, you'll need to cook your spaghetti squash. There are several ways to cook spaghetti squash. Your options vary from oven, microwave, and even instant pot.
Be sure to remove the ends of the squash before slicing to make it easier to do so.
- Microwave instructions: Slice the squash in half lengthwise, remove the seeds, and microwave for about 15 minutes. Scrape the flesh for spaghetti strands. You could also microwave the squash whole after poking the flesh all over and microwaving for about 25-30 minutes, turning the squash halfway through the cooking process.
- Instant Pot instructions: Slice the squash in half lengthwise, remove the seeds, and pressure cook for 7-8 minutes. Scrape the flesh for spaghetti strands.
- Oven instructions: bake in the oven. Slice the squash in half, remove the seeds, place the squash face down on a baking sheet, and roast at 400 degrees for about 40-45 minutes. Then, proceed to scrape the flesh for spaghetti strands.
Once the squash is ready, it's time to make the keto Alfredo sauce and topping.
In a small saucepan, melt the butter over medium-low heat. To the melted butter, add the heavy cream, garlic powder, onion powder, salt, pepper, nutmeg powder, softened cream cheese, and shredded parmesan cheese.
Cook the sauce for about 5-7 minutes, or until the cheeses melt completely and the sauce thickens.
I added a simple cheese topping to the casserole that complements the dish very well.
To make the topping, just combine the mozzarella cheese and shredded parmesan cheese. Then, top the casserole before baking.
To assemble the casserole, grease well with butter in a 13x9-inch baking dish.
Place the spaghetti squash strands into the baking dish, then pour the Alfredo sauce over the squash and toss well, making sure everything gets coated.
Then add the cheese topping and bake the casserole for 35-45 minutes until golden brown. If at the 45-minute mark, your casserole isn't brown on top, my favorite method is to broil at high for 3-5 minutes until golden brown.
Alternatively, you could fill the squash shells with the prepared casserole and then place the squash boats in a large casserole dish or rimmed baking sheet.
Lastly, garnish with fresh chopped parsley, and enjoy!
Would you like to save this?
We'll email this post to you, so you can come back to it later!
Tips For The Best Spaghetti Squash Alfredo Casserole
For the best texture, avoid overcooking the spaghetti squash. You want the strands tender enough to remove easily with a fork but not so soft that they become mushy once the casserole goes back into the oven.
If your cooked spaghetti squash seems especially watery, allow the strands to drain before combining them with the Alfredo sauce. Removing excess moisture helps keep the finished casserole creamy rather than watery.
For a smoother Alfredo sauce, make sure the cream cheese is softened before adding it to the saucepan. Cook the sauce gently over medium-low heat and stir until the cheeses are completely melted.
Freshly grated Parmesan also melts more smoothly than many packaged pre-shredded varieties.
Finally, if the cheese topping has not browned by the time the casserole is heated through, place it briefly under the broiler.
Watch it carefully since the cheese can go from golden to overly browned very quickly.
Can I Add Chicken To Spaghetti Squash Alfredo?
Absolutely. However, if you're looking for a heartier version made specifically with chicken, I recommend making my Keto Chicken Alfredo Casserole instead.
That recipe was developed as a complete meal with chicken, spaghetti squash, homemade Alfredo sauce, and a cheesy topping, while this recipe is intended to work beautifully as a meatless side dish or lighter meal.
Can I Make This Casserole Ahead?
You can cook the spaghetti squash ahead of time and store the strands in the refrigerator until you're ready to assemble the casserole. This can make preparation much faster on the day you plan to serve it.
If the refrigerated squash releases any moisture, drain it well before combining it with the Alfredo sauce.
How To Store And Reheat Leftovers
Store leftover spaghetti squash Alfredo casserole in an airtight container in the refrigerator for up to three days.
Reheat individual servings gently in the microwave or warm a larger portion in the oven until heated through. Because Alfredo sauce can separate when frozen and thawed, I do not recommend freezing the fully assembled casserole.
Recipes That Pair Well With This Side Dish
Although I am classifying this as a side dish, you could, of course, make it a main meal and just serve it with a side salad.
More Keto Spaghetti Squash Recipes
If you are a fan of low-carb spaghetti squash recipes the following are some recipes you should plan on trying next:
Tag Us
I sure hope you will give this spaghetti squash recipe a try. Once you do, make sure you remember to tag us on Instagram, Facebook, and Pinterest.
It's what keeps us encouraged to keep sharing and perfecting our recipes. Also, check out our Amazon Store for our recommendations.
Join Our Jesus And Keto Movement
Our family came to the keto diet looking at it from a Christian perspective; it's the filter we choose to see from.
When we decided to combine our Christian faith and the keto diet, we did so in hopes of finding lasting transformation.
To say we needed God's intervention is to put it mildly. When we followed the Holy Spirit's lead to embrace the ketogenic diet and combine it with our faith, we got on the path to real transformation. I
If you are looking for a Christian group that is using the keto diet to transform their lives, we invite you to join our Private Facebook Group and see if it's not the key you have been missing.
Grab Our Books!
In case you don't know, we have authored two books for you, Essential Keto Bread and Essential Keto Desserts, both inspired by your requests over the years.
It's my prayer these keto cookbooks will help make keto a delicious breeze for you.
Be sure to request our FREE Jesus and Keto E-Book (First 7 Days). We hope it blesses you.
Fittoservegroup Keto App
Looking for a fast way to access our keto recipes? We've got you covered. There's an app for that.
Yup, there's a Fit To Serve Group App that will make your keto diet a delicious breeze! Access hundreds of recipes that are all sugar-free, gluten-free, and keto-friendly.
Enjoy early access to recipes before they go live on the website. Plus, there are bonus recipes that are exclusive to the app. Make your own personal cookbooks that you can use to organize your favorite recipes.
Search recipes by title, ingredients, keywords, and categories, and of course, every recipe shows complete nutritional facts.
Get the Fit to Serve Group App for easy-to-follow keto recipes made with easy-to-source ingredients.
The app is loaded with hundreds of yummy recipes for breakfast, lunch, dinner, snacks, and even desserts!
Learn more by visiting our Fit To Serve Group App Page.
Keto Spaghetti Squash Alfredo Casserole
This Keto Spaghetti Squash Alfredo Casserole is creamy, cheesy, and perfect when you're craving pasta without all the carbs! Tender spaghetti squash is tossed with a rich homemade low-carb Alfredo sauce, topped with mozzarella and Parmesan, and baked until bubbly and golden. Naturally gluten-free and delicious as a keto side dish or light meatless meal.
Ingredients
- 1 large spaghetti squash, about 3.5 pounds
- ¼ cup of unsalted butter
- 2 ½ cups of heavy cream
- 2 ounces of softened cream cheese
- ½ teaspoon of salt
- ½ teaspoon of garlic powder
- ½ teaspoon of onion powder
- ½ teaspoon of black pepper
- ¼ teaspoon of nutmeg powder
- 1 cup freshly grated parmesan cheese
Cheese Topping
- 2 cups of shredded mozzarella cheese
- 1 cup of shredded parmesan cheese
Garnish
- ¼ cup of chopped fresh parsley
Instructions
- Preheat the oven to 400 degrees if cooking the spaghetti squash in the oven. Otherwise, refer to the notes section for other ways to cook the squash.
Spaghetti Squash Prep
1. Cut the ends of the spaghetti squash and cut the squash lengthwise.
2. Place each half of the spaghetti squash facedown onto the prepared baking tray. Bake the squash in the 400 degrees preheated oven for 45-50 minutes or until a knife inserted into the squash enters easily.
3. Flip the squash to the cut side and using a fork remove the seeds, then proceed to rake the squash with your fork to remove the spaghetti strands from the squash. This should happen easily. If not return the squash back into the oven and cook for another 10-15 minutes. If ready turn off the oven.
4. Once the squash is fully cooked and the spaghetti-like strands can be removed easily from the skin of the squash allow the squash to cool for about 15 minutes before removing scraping all the flesh of the squash.
5. Place all the spaghetti squash strands into a large bowl. Set it aside.
6. Proceed to make the keto alfredo sauce.
Keto Alfredo Sauce
- In a small saucepan, melt the butter over low heat.
- To the melted butter add the heavy cream, garlic powder, onion powder, salt, pepper, nutmeg powder, softened cream cheese, and shredded parmesan cheese.
- Cook the sauce over medium-low heat for about 5-7 minutes until the cheeses melt and the sauce thickens. Set it aside
Cheese Topping
- In a small bowl combine the shredded mozzarella cheese and shredded parmesan cheese. Top the casserole before baking.
Assembling The Keto Spaghetti Squash Alfredo Casserole
- Preheat the oven to 350 degrees.
- In a large bowl, add the spaghetti squash, and the prepared alfredo sauce, toss well. Stir well making sure that everything is coated well with the sauce.
- Spread the alfredo mixture evenly into the buttered casserole dish.
- Top evenly with the cheese topping.
- Bake the casserole for 35-45 minutes until golden brown.
- Broil for 3-5 minutes if at the 45-minute mark the casserole hasn't browned.
- Store leftovers in the refrigerator for up to 3 days.
Notes
Ways To Cook Spaghetti Squash:
- Microwave instructions: Slice the squash in half lengthwise, remove the seeds, and microwave for about 15 minutes. Scrape the flesh for spaghetti strands. You could also microwave whole after poking the flesh all over and microwaving for about 25-30 minutes turning the squash halfway through the cooking process.
- Instant Pot instructions: Slice the squash in half lengthwise, remove the seeds, and pressure cook for 7-8 minutes. Scrape the flesh for spaghetti strands.
- Oven instructions: To bake in the oven. Slice the squash in half remove the seeds and place face down on a baking sheet and roast at 400 degrees for about 40-45 minutes. Then proceed to scrape the flesh for spaghetti strands.
For a fun presentation, rather than placing the prepared Alfredo into a casserole dish, you could alternatively place it into the squash shells and then place the spaghetti squash boats in a large casserole dish or rimmed baking sheet before baking.
Store any leftovers in an airtight container in the refrigerator for up 3 days. Due to the cream sauce, I do not recommend freezing this casserole. I find that the sauce tends to separate once it thaws.
Nutrition Information:
Yield:
12Serving Size:
1Amount Per Serving: Calories: 275Total Fat: 19.5gSaturated Fat: 13.1gCholesterol: 85mgCarbohydrates: 7.5gNet Carbohydrates: 5.7gFiber: 1.8gSugar: .1gProtein: 7g
Debora Depczynski says
Nutmeg powder is mentioned in the instructions but not the ingredient list. How much nutmeg powder should be used?
Hilda Solares says
Thanks for pointing this out Debora. I'll add it now. It is 1/4 teaspoon.
Allison Twite says
Hi, I see it yields 12 servings but do you have an actual measurement for one serving?
Hilda Solares says
Hi Allison, I would say a serving is 1 1/2 cups. I hope this helps.