Cheesy Spaghetti Squash Casserole Recipe

Name: Cheesy Spaghetti Squash Casserole Recipe
Prep time: 20 min
Cook time: 1 h 10 min
Total time: 20 min
Yield: 6
Cuisine: American
Ingredients: 1 large spaghetti squash; 1 tablespoon olive oil; 1 teaspoon garlic powder; 1 teaspoon onion powder; Salt and black pepper to taste; 1 pound ground Italian sausage (mild or hot); 1/2 yellow onion, diced; 2 cloves garlic, minced; 1 (24-ounce) jar marinara sauce; 1 cup whole milk ricotta cheese; 1 large egg; 2 cups shredded mozzarella cheese, divided; 1/2 cup grated Parmesan cheese; Fresh basil for garnish (optional)

The first time I tried to make this cheesy spaghetti squash casserole, I almost gave up on cooking forever. I was so proud of my whole squash, I just shoved it in the oven, whole. An hour later, it was rock hard. My husband came in, poked it with a fork and just started laughing. I learned the hard, smoky way that you gotta cut that thing in half first. Now it’s our favorite cozy dinner, but man, it did not start out that way.

Recipe Card

Recipe Title	Cheesy Spaghetti Squash Casserole Recipe
Servings	6
Prep Time	20 minutes
Cooking Time	1 hour 10 minutes
Calories	approx. 320 per serving

Ingredients

1 large spaghetti squash
1 tablespoon olive oil
1 teaspoon garlic powder
1 teaspoon onion powder
Salt and black pepper to taste
1 pound ground Italian sausage (mild or hot)
1/2 a yellow onion, diced
2 cloves garlic, minced
1 (24-ounce) jar of your favorite marinara sauce
1 cup whole milk ricotta cheese
1 large egg
2 cups shredded mozzarella cheese, divided
1/2 cup grated Parmesan cheese
Fresh basil for garnish (if you’re feeling fancy)

That ground sausage is key for me. I once used plain ground turkey to be “healthier” and it was so bland we had to douse it in hot sauce. The fat from the sausage gives so much flavor, trust me. And don’t skip the egg with the ricotta! I did once and the whole thing was kind of soupy and didn’t set right.

Directions

Preheat your oven to 400°F (200°C).
Carefully cut the spaghetti squash in half lengthwise. This is the scary part, use a sharp, sturdy knife.
Scoop out the seeds and stringy guts from the center with a spoon.
Drizzle the cut sides with olive oil and rub it all over. Sprinkle with garlic powder, onion powder, salt, and pepper.
Place the halves cut-side down on a baking sheet. Roast for about 40-45 minutes, or until the flesh is tender and easily shreds with a fork.
While the squash is roasting, brown the Italian sausage in a large skillet over medium-high heat, breaking it up as it cooks.
Add the diced onion to the skillet and cook for 5-6 minutes until softened. Add the minced garlic and cook for one more minute until fragrant.
Stir in the marinara sauce and let the whole thing simmer for about 10 minutes. Take it off the heat.
In a medium bowl, mix together the ricotta cheese, egg, 1 cup of the mozzarella, and the Parmesan cheese.
Once the squash is done, let it cool until you can handle it. Then use a fork to scrape all the flesh into “spaghetti” strands into a large bowl.
Add the sausage and marinara mixture to the bowl with the squash strands and mix it all up really well.
Spread half of the squash mixture into a 9×13 inch baking dish.
Dollop the entire ricotta cheese mixture over this layer and spread it as evenly as you can.
Top with the remaining squash mixture, then sprinkle the last cup of mozzarella cheese over the top.
Bake for 25-30 minutes, until the cheese is melted and bubbly and the edges are a little golden. Let it sit for 5-10 minutes before serving.

The part where you scrape the squash is weirdly satisfying, but be careful. I burned my fingertips so many times by being impatient. Let it sit for a good 15 minutes, it’s still plenty hot to work with. And that resting time at the end is not a suggestion! If you cut in right away, it’ll be a cheesy puddle on your plate instead of neat slices.

I love this dish because it feels like a giant hug. It’s my go-to for potlucks now, but the first time I brought it, I forgot to tell people it was squash. My friend’s dad ate two helpings before saying, “This is the weirdest pasta I’ve ever had, but it’s good!” It’s a total crowd-pleaser, even for picky eaters.

The leftovers are maybe even better than the first night. It reheats like a dream in the microwave for a quick lunch. I’ve tried freezing it and the texture gets a little watery, but it’s still edible if you’re desperate. It’s one of those easy dinners that doesn’t feel like a compromise.

If I were to change one thing, I’d maybe add some chopped spinach to the ricotta layer sometimes for a little extra green. I tried mushrooms once and my kids picked every single one out, so that was a fail. It’s a really forgiving recipe, so play around with what your family likes.

Nutrition Info (per serving)

Calories	Carbs	Fat	Protein
320	18g	19g	22g

I’m always surprised how filling this is for not a ton of calories. It’s a great healthy swap for a classic pasta bake. You can definitely make it lighter by using lean ground turkey and part-skim cheeses, but like I said, the flavor changes. For my gluten-free friends, this is a total win.

Ingredient Swaps

Ingredient	Substitution
Italian Sausage	Ground beef, turkey, or chicken
Ricotta Cheese	Cottage cheese (blended smooth)
Marinara Sauce	Alfredo sauce for a creamy version
Mozzarella	An Italian cheese blend

I’ve tried most of these swaps. The cottage cheese one works surprisingly well if you blend it first, otherwise you get weird curds. Alfredo sauce makes it super rich, almost too rich for me. And using ground beef is fine, but you’ll wanna season it really well with some Italian seasoning to make up for what the sausage usually brings.

Tips

Microwave the whole squash for 2-3 minutes before cutting to soften the shell and make it safer to slice.
Really press down on the squash layers in the dish with a spatula to help it all hold together when you serve it.
If your squash seems watery after roasting, put the strands in a clean kitchen towel and squeeze out the excess moisture.

That last tip I learned after a major casserole fail. I didn’t drain the squash at all and it was basically swimming in liquid after baking. We had to eat it with a slotted spoon, it was a mess. A little squeeze makes a world of difference in the final texture, I promise.

FAQ

Can I make this ahead of time?
Oh totally. I assemble the whole thing the night before, cover it, and keep it in the fridge. Just add maybe 10 extra minutes to the baking time since it’ll be cold from the fridge. It’s a lifesaver for busy weeknights.

My squash won’t get tender, what did I do wrong?
This happened to me too! It usually means your squash was a real monster. Just put the halves back in the oven, cut-side down, and check it every 10 minutes. It might need a full hour. Ovens can be so finicky.

Is there a faster way to cook the squash?
You can poke the whole squash a bunch of times with a fork and microwave it for 10-15 minutes. Let it cool before cutting it in half and scraping. It works in a pinch, but I think the flavor is better and less watery from roasting in the oven.

That’s everything I know about making this Cheesy Spaghetti Squash Casserole! Hope you give it a try, and if you mess it up, you’re in good company—I do it all the time.