Spaghetti Squash Casserole -

A spaghetti squash casserole with only 6 ingredients – and two of them are cheese? Yes please, sign me right up! 

If you’re a Percolate newsletter subscriber, then you might remember when I shared this handy kitchen hack about how to slice open a large squash without chopping your whole hand off in the process.  You’re gonna want to remember that tip because it’s going to come in sooo handy with this recipe: Extra Cheesy Spaghetti Squash Casserole.

If you haven’t hopped on the spaghetti squash train yet, you are seriously missing out.

Spaghetti squash is pretty much just what it sounds like; squash that, once roasted, can be scraped clean in long strands that resemble spaghetti noodles. It’s super flavorful and crazy good for you; spaghetti squash is packed full of B vitamins, omega-3 and omega-6 healthy fats, fiber, and is low in calories.

Spaghetti squash’s banging nutritional facts count just a little bit more when you see my recipe this week, which has added butter and two types of cheese. Hey, we can afford it, right? The last few weeks I’ve shared healthy versions of standard recipes in Spinach Lasagna Roll-Ups and Veggie Skillet Chili, so this week we can let ourselves live a little.

This spaghetti squash casserole technically counts as a weeknight meal, since the dish itself comes together in under 30 minutes.

However, spaghetti squash needs to roast in the oven for about 45 minutes to an hour before you can remove those delicious strands. On a busy weeknight, I’m betting you ain’t got time for that. So I recommend roasting the squash one night and making the casserole the next. Or, if you’re feeling like truly giving your future self a high five, roast a couple of squashes and then freeze the cooked strands. They’ll keep for up to three months in the freezer when tightly covered.

A spaghetti squash casserole that's only 6 ingredients - and two of them are cheese? Yes please, sign me up! This casserole makes a great weeknight meal.
Spaghetti Squash Casserole
Prep Time
45 mins
Cook Time
20 mins
Total Time
1 hrs 5 mins
Servings: 4
Author: Ruthy Kirwan
To roast the spaghetti squash
  • 1 large spaghetti squash about 2-3 pounds
  • 2 tablespoons olive oil
  • 1/2 teaspoon salt
for the casserole
  • 4 cups cooked spaghetti squash see instructions below
  • 2 cups (8 oz) sliced mushrooms
  • 1/4 cup melted butter
  • 2 cloves garlic, minced
  • 1/2 cup grated parmesan cheese
  • 1/2 cup shredded gouda
to roast the spaghetti squash:
  1. Preheat the oven to 400*F. 

  2. Slice the spaghetti squash in half and lay the open slices on a sheet pan lined with aluminum foil, skin side down.
  3. Evenly drizzle the spaghetti squash with olive oil.
  4. Evenly sprinkle the spaghetti squash with salt.

  5. Remove the squash and set aside until cool enough to handle. Use a fork to scrape the longs strands of squash from the inside, leaving only the skin behind.

to make the casserole:
  1. Preheat the oven to 350*F. 

  2. In a large bowl, combine the spaghetti squash, mushrooms, butter, garlic and parmesan cheese. Toss to combine.
  3. Pour the mixture into a large ovenproof casserole dish, at least 4QTs (9"x13")
  4. Top the spaghetti squash mixture with the shredded gouda cheese, spreading the cheese evenly.
  5. Bake 15-20 minutes, until the mushrooms have cooked through and the melted cheese has lightly browned and is bubbling.
  6. Remove and let cool slightly before serving.
  7. Roast the spaghetti squash for 35-50 minutes, depending on the size of the squash. The squash is ready when the insides are soft and fork tender.

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