Keto Spaghetti Squash Casserole with Alfredo Sauce

This Keto Spaghetti Squash Casserole with creamy Alfredo sauce is calling all pasta lovers!

Crunchy vegetable spaghetti smothered with a gluten-free creamy garlic sauce topped with broiled cheese and only 6 grams of net carbs. A delicious, comforting keto recipe that the whole family will love.

this Recipe

Are you ready for fall recipes welcoming spaghetti squash as the new keto vegetable into your plate? But first, let’s talk about spaghetti squash.

What’s spaghetti squash?

Spaghetti squash is a winter vegetable also known as vegetable spaghetti or noodle squash. Its name came from its yellow-orange flesh that forms spaghetti-like strands when the cooked flesh is pulled apart with a fork.

Spaghetti squash recipes are one of these comforting meals, perfect for replacing a lasagna!

Is spaghetti squash keto-friendly?

Yes, you can eat spaghetti squash on a keto diet. It is a very low-carb and low-calorie vegetable, with only 5.5 grams of net carbs and 31 kcal per cup.

It means it has a similar amount of carbs as its keto vegetable friends: cooked eggplants or Brussels sprouts.

Spaghetti squash is an amazing vegetable to create tasty keto recipes for pasta lovers. In fact, the spaghetti strands from this squash are firm, long, tasteless, and truly mimic the texture of real spaghetti pasta.

How to cook a spaghetti squash casserole?

It is pretty easy to make a baked spaghetti squash casserole. First, you need to bake your squash to release the vegetable spaghetti. Let’s see how to cook spaghetti squash!

If you want to see this recipe a different way, have a look at my story: making the spaghetti squash casserole!

There are a few different ways to cook spaghetti squash depending on:

• How you cut the squash: halved lengthwise, crosswise, or sliced in rings.
• The cooking methods: oven-baked, steamed in a crock-pot, microwaved.

Here I am sharing the best method to bake spaghetti squash for the best spaghetti squash casserole. It means that the flesh will be crunchy, firm, slightly caramelized, but not watery or mushy!

First, preheat the oven to 400F (200C), the fan-forced mode works faster, and it is preferable. Then, line a large baking tray with parchment paper and lightly oil the paper.

Cutting the squash

The best way to cut a spaghetti squash to bake it evenly is to cut it lengthwise. First, trim the ends. Then, stand the squash up on one steam and cut to obtain two spaghetti squash boats.

Next, scoop out all the seeds and discard them.

Finally, place each spaghetti part with the flesh side down onto a baking sheet covered with a piece of parchment paper.

Make sure you brush the paper or the squash in contact with the paper with olive oil. Finally, bake for 30-40 minutes.

Baking time

The baking time is the key. If you bake your squash too much, the spaghetti squash will not form firm noodles. It will be mushy and soft. So always check the baking process by:

• Checking the color of its skin – when it starts to darken or brown, it is cooked!
• Inserting a knife into the squash shell after 30 minutes. If the shell is soft and the knife goes through even a little bit, remove the tray from the oven, flip one squash boat and start grating the flesh with a fork.

If the strands are yellow/golden, slightly caramelized on the sides, and come out easily, it means it is cooked through.

How to make the vegetable spaghetti?

Flip over the two baked spaghetti squash boats and let the steam come out.

When the steam is out, wear a mitten and hold the squash with one hand, and with the other hand, pull apart the flesh using a fork.

It will form long, crunchy vegetable noodles, about 5 cups per spaghetti squash. Set aside on a baking dish and discard the squash shells.

Keto Alfredo sauce

This is a cheesy spaghetti squash casserole recipe using a creamy Alfredo garlic sauce.

To make the sauce, first, melt butter into a saucepan, then add heavy cream and shredded cheese – Parmesan is the best!

Stir constantly until the sauce is thick and forms strings of cheese.

Now add chopped parsley, salt, and garlic, and an extra 1/2 cup of unsweetened almond milk to make a cheesy sauce, easy to pour over the baking dish.

Pour the sauce over the baking dish containing the baked squash spaghetti.

Use a spoon to combine the sauce into the vegetable noodles to cover all spaghetti evenly and create a creamy garlic spaghetti squash casserole.

Meat sauce: chicken Alfredo casserole

For the chicken Alfredo casserole lovers, you can adapt the recipe by adding 2 shredded chicken breasts into the casserole.

First, combine the cooked shredded chicken into the creamy sauce and pour it onto the baking dish containing the baked squash spaghetti.

Finally, stir to evenly cover the spaghetti with the sauce and top the casserole with shredded mozzarella. Bake on medium-high heat (180C/350F) for 15 minutes to broil the cheese on top.

Can I make this casserole ahead?

Yes, you can make ahead your spaghetti squash casserole. There are two options to make this keto casserole recipe 24 hours to 48 hours before serving, depending on how you want to serve the dish.

• Meal preparation for single serves – follow the entire recipe, store the whole casserole in the fridge, wrap the baking dish with plastic wrap. Then, rewarm by single-serves in the microwave, saucepan, or oven until piping hot.
• Family gatherings – if you want to serve this vegetarian spaghetti squash casserole beautifully, I recommend assembling the casserole just before serving. It means that the day before, you pre-bake the squash spaghetti and Alfredo sauce and store them separately in the fridge, in 2 airtight containers. Then, assemble the casserole just before serving, bake following the recipe and serve.

An egg-free breakfast casserole

We all sometimes love an egg-free keto breakfast, and this spaghetti squash breakfast casserole is perfect for it.

Your casserole will store for up to 3 days in the fridge or freeze in single-serve airtight containers.

Then, rewarm your portion in the microwave or saucepan, or hot oven just before serving.

More keto low carb casserole recipes

If you love this low-carb spaghetti squash casserole recipe, you may also want to try my other low-carb casserole recipes below!

Leave me a comment below if you want to see more spaghetti squash recipes on the blog! And if you made this simple spaghetti squash casserole, don’t forget to share a comment or review below.

XOXO Carine