Spaghetti squash noodles can be substituted in many other pasta dishes or served topped with regular pasta sauce saving you loads of carbs — so what’s not to love?!

My Spaghetti Squash Casserole combines fresh “squaghetti” noodles with sautéed spinach, red bell pepper, and garlic plus three kinds of cheese to create a rich, yet delicate dish.

This creamy Spaghetti Squash Casserole is a cheesy vegetarian, keto-friendly, low-carb, gluten-free casserole. That covers just about all the bases!

Looking for more vegetarian main dishes? My Easy Skillet Vegetable Lasagna is loaded with zucchini, yellow squash, onions, and mushrooms and is ready in just 30 minutes! Or, you may like this Healthy Butternut Squash Soup — it’s perfectly creamy and delicious. 

Spaghetti Squash Casserole: behind the recipe

Confession time. The first time I made this recipe was my very first experience cooking spaghetti squash. Truth! I’m not sure why it’s took me so long to try this vegetable, but let me tell you that this first time will not be my last.

Unlike other veggies that you spiralize to make noodles, once cooked the flesh of a spaghetti squash can be separated into spaghetti-like strands (or squaghetti as I like to call it) simply by scraping it out with a fork.

One three-pound squash will make enough squaghetti to equal around a pound of pasta noodles — a great alternative when you are watching your carb intake!

Key ingredients and substitutions

• Spaghetti squash — Choose a squash that doesn’t have cracks or spots on its skin and be sure the stem is not withered and dry.
• Red bell pepper — Any color bell pepper will work, but I like the sweetness of red bell peppers.
• Onion — A yellow or sweet onion along with fresh garlic adds the aromatic flavors to this dish. To make it heartier, toss in mushrooms, sundried tomatoes, or any other veggie you find in your fridge.
• Spinach — I use fresh baby spinach, but you can also use frozen chopped spinach. Just be sure to thaw and squeeze out any liquid before adding to the casserole.

Wow! This is AWESOME! I’ve been on a ketogenic diet for a few months, and this meal just hits the spot and tastes so indulgent! Thank you for sharing this!

— Kim

How to make spaghetti squash casserole

STEP 1 | Cook the squash

• Cut the spaghetti squash in half length-wise and use a large spoon to scrape and scoop out the seeds.
• Lay the squash cut side down in a baking dish and pour in 1/2 cup water.
• Bake the squash until it is tender and easily be pierced with a fork.
• Remove the squash from the pan and let rest until it is cool enough to handle.
• Gently scrape all the flesh away from the rind/peel with a fork.

STEP 2 | Sauté vegetables

1. Sauté diced onions and red bell pepper until tender, then add minced garlic and cook another minute until fragrant.
2. Toss in fresh spinach and cook until wilted.

STEP 3 | Add cheese and bake

1. Add a block of softened cream cheese to the pan with the veggies and stir until melted.
2. Gently stir in the spaghetti squash and transfer the mixture in a lightly greased casserole dish.
3. Top with mozzarella and parmesan cheese and bake until hot, bubbly, and the cheese has a golden crust.

Frequently asked questions

More delicious vegetable recipes

• Zoodle Ratatouille is a composition of seasonal vegetables—zucchini, onions, sweet bell peppers, and tomatoes—cooked with olive oil and garlic.
• Broccoli Rice and Cheese Casserole is a delicious side dish for barbecue chicken, pork chops, or even meatloaf. A creamy rice dish using fresh broccoli and mushrooms, this casserole also uses both cheddar and Parmesan cheese for extra cheesy goodness!
• Grilled Corn and Mushroom Risotto starts with grilling fresh corn, mushrooms, and poblano chili peppers to create this creamy and hearty one-dish meal.
• Balsamic Roasted Parsnips and Carrots are topped with a feta cheese “salad” of lemon, parsley, and dried cherries.
• Roasted Spaghetti Squash with Marinara — low-carb spaghetti option!
• More side dish recipes!
  

Please share!

Your shares are how this site grows and I appreciate each one. Do you know someone who would enjoy this recipe? I’d love it if you would share it on Facebook or on your favorite Pinterest board!