Dive into a bowl of warm, savory delight with this Spaghetti Squash Alfredo Casserole. Each bite is filled with undeniable flavor, all with just 5 ingredients. This dish doesn’t play around.

There’s something to be said for coming home from a long day of work, putting together a quick casserole, plopping it in the oven for a bit, and then enjoying a nice, warm bowl of creamy, cheesy, savory delight.
It’s just too comforting to handle, like a big, warm hug wrapped up in a yummy layered baking dish.
For me, casseroles are even better when they’re simple to make, use as little ingredients as possible, and provide maximum flavor. Luckily, that’s exactly what this spaghetti squash Alfredo casserole does. It’s cheesy, jam-packed with veggies, and oh, so delicious.
Trust me, you’re gonna love it.
Reader rating
“This recipe was the only way my family have ever eaten more than a bite of spaghetti squash so this must be good! I liked it.” —Dara
Here’s what you’ll need
I love a good low-ingredient recipe, and this one fits the bill each and every time. Spaghetti squash casserole calls for only 5 ingredients total, meaning less time spent gathering items at the grocery store and more time spent enjoying each savory bite!
- Spaghetti Squash: To start this recipe, snag two large, bright yellow spaghetti squash. For the best results, choose two that are void of soft spots and feel firm to the touch.
- Broccoli: Next up in this recipe, we’ll be using 2 cups of broccoli florets. Cauliflower would also work well here!
- Olive Oil: We will use olive oil to crisp up the spaghetti squash and the broccoli in the oven.
- Alfredo Sauce: Rather than making it from scratch, we’re opting for the store bought stuff (because who has time for that on a weeknight?). Choose your favorite Alfredo, 16-oz of any brand or recipe will work.
- Shredded Mozzarella Cheese: Mix half of it into the casserole to lace your Alfredo casserole with cheesy deliciousness. Sprinkle the rest on top and broil to crispy brown perfection.
How to make Alfredo spaghetti squash
Cooking dinner doesn’t have to be difficult or time consuming, and this recipe proves that. In just 45 minutes (of which only 5 are devoted to prep time), you’ll have a veggie-packed casserole fit for any evening occasion. Share it with guests, freeze it for later, or enjoy a heaping plate to yourself right now!
Step 1: Prep the spaghetti squash
To start, preheat the oven to 400°F (204°C). Cut the spaghetti squash in half lengthwise and scoop out the seeds. Drizzle the insides with most of the olive oil and rub to evenly coat the squash. Place the halves cut-side down on a baking sheet and prick the outside with a fork. Then, spread the broccoli florets onto the same baking sheet and drizzle with the remaining olive oil, tossing to coat evenly.
Step 2: Roast the squash
Roast for about 30 minutes, or until the squash is fork tender but still a little firm. The broccoli should be lightly browned (if it cooks more quickly, take it out of the oven earlier than the squash). When the squash is finished, flip it over and allow it to cool enough to touch.
Step 3: Spaghettify the squash and broccoli
Next, use a fork to scrape the strands from the inside of the spaghetti squash.
Step 4: Assemble the casserole
In a large bowl, stir together the spaghetti squash strands, roasted broccoli, Alfredo sauce, and ½ cup of the cheese. Pour everything into a large casserole dish and gently pack it so that it’s an even layer. Then, sprinkle with the remaining ½ cup of cheese.
Step 5: Broil until melty
Finally, switch the oven to broil and add the casserole dish. Cook for just a few minutes, watching closely until the cheese has melted and turned golden brown.
Spice up your casserole with extra add-ons
When making your casserole, there are a number of ways that you can customize it and add ingredients to make it your very own.
Get spicy
Add your favorite spices and seasonings to give your dish extra flavor. You can try oregano, garlic powder, onion powder, or even red pepper flakes.
Add veggies
Pack in the extra veggies by using whatever you’d like! You can use green peppers, red onions, or even sautéed mushrooms.
Recipes that pair well with spaghetti squash Alfredo casserole
Once your Alfredo is ready to enjoy, it needs a yummy sidekick! Here are some delicious (and easy!) dishes that pair well with this casserole and can be ready in only a few minutes.
Ingredients
- 2 large spaghetti squash
- 2 cups broccoli florets 150 g
- 2 Tbsp olive oil 30 mL
- 1 16-oz jar Alfredo sauce about 1 ½ cups, 453 g
- 1 cup shredded mozzarella cheese divided, 100 g
Instructions
- Prep: Preheat oven to 400°F (204°C). Cut spaghetti squash in half lengthwise and scoop out the seeds. Drizzle the insides with most of the olive oil and rub to evenly coat. Place cut-side down on a baking sheet and prick the outside with a fork. Spread broccoli florets onto the same baking sheet and drizzle with remaining olive oil, tossing to coat it evenly.
- Roast: Roast for about 30 minutes, or until squash is fork tender but still a little firm. Broccoli should be lightly browned (if it cooks more quickly, take it out of the oven earlier than the squash). When squash is finished, flip it over and allow to cool enough to touch.
- Spaghettify: Use a fork to scrape strands from the inside of the spaghetti squash.
- Assemble: In a large bowl stir together spaghetti squash strands, roasted broccoli, Alfredo sauce, and ½ cup of the cheese. Pour into a large casserole dish and gently pack so that it's in an even layer. Sprinkle with remaining ½ cup of cheese.
- Broil: Switch the oven to broil and add casserole dish. Cook for just a few minutes, watching closely until the cheese has melted and turned golden brown.
Dara says
Family thought it would be “too much cheese” besides the Alfredo sauce, we’re lactose intolerant. So I made the sauce with soy milk (thickest) instead of cream, but with real butter and parm. I ended up adding GF spaghetti noodles to this, spaghetti squash is just not a hit here. This recipie was the only way they’ve ever eaten more than a bite of spaghetti squash so this must be good! I liked it.
Sarah says
Happy to hear you liked it, Dara! Those substitutions sound tasty! 😀
GW says
Loved it. What a great twist with squash
Sarah says
Thanks so much! 😀
Aryan says
What does one serving size equal?
Sarah says
A half of a spaghetti squash (this serves 4) 😀
Cathy Moody says
Great recipe. Will probably add sautéed mushrooms, onions, and garlic the next time.
Jasvir Singh says
What would be the best way to prepare this to freeze, and directions to thaw and cook later?
Sarah Bond says
I would freeze it in individual portions, tightly sealed in the freezer. When ready to enjoy, either pop it directly in the oven, or thaw and microwave it 😀