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This cheesy baked spaghetti squash casserole is a winner! It stars Italian style flavors: pesto, artichoke, mozzarella, and Parmesan cheese.

Spaghetti squash casserole
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Are you a spaghetti squash fan? But really: who wouldn’t be a fan of those long, nature-made noodles? Spaghetti squash is making it into all sorts of dishes that squash wouldn’t be caught dead in decades earlier. Spaghetti squash mac and cheese. Spaghetti squash pad Thai. And here is Alex and my latest creation: spaghetti squash casserole! This casserole is an Italian style spin on the traditional, featuring basil pesto, sundried tomatoes, mozzarella cheese, and Parmesan cheese. It’s seriously hearty and satisfying. (Our 2 year old was all over it!) Ready to get started?

Spaghetti squash casserole

Spaghetti squash casserole: Italian style!

There are all sorts of spins on spaghetti squash casserole: this version uses Italian flavors to make a tangy, savory and cheesy version. Here are the major features:

  • Basil pesto is swirled into the squash noodles, which brings an overall garlicky savoriness.
  • Fresh mozzarella cheese creates gooey pockets and grated Parmesan cheese brings texture and even more savory flavor.
  • Artichoke hearts and sundried tomatoes bring in a tangy Italian-style element.
Spaghetti squash casserole

Is it a main or a side dish?

One important question before we start: is this spaghetti squash casserole a main or a side? It’s the same question as mac and cheese, really. This casserole would make a stand-out side dish for entertaining. We could imagine it on the table at a pitch in or potluck with other hearty sides. It would be perfect for holiday meals like Thanksgiving or Christmas dinner, but it really works anytime that spaghetti squash is in season. It’s a great vegetarian and gluten free casserole option that works for various diets.

However: this casserole does take quite a while to prepare. The full prep time is almost an hour and a half. We’ll be honest: Alex and I don’t spend this much time on a side dish if we’re not entertaining. So, if we were making it just for us, we’d serve it as a main dish! Add a green salad and green beans and suddenly it’s a vegetarian main dish.

This casserole could also be a hearty savory brunch option! It would be perfect for brunch for holiday entertaining, or a baby shower or bridal shower brunch.

Spaghetti squash casserole

Can you speed up prep time on spaghetti squash casserole?

You can! There are some make ahead tips and short cuts we have in mind. Here’s what we’d suggest if you’re running low on time:

  • Make the spaghetti squash in advance. One idea to speed up prep time is to make the spaghetti squash in advance! If you meal prep, roast or pressure cook the spaghetti squash up to 2 days in advance. Refrigerate, then assemble the casserole. Just bake it a little longer until the squash is warmed through.
  • Pressure cook the spaghetti squash. Got an Instant Pot? If so, our Instant Pot spaghetti squash takes just 30 minutes from start to finish. It’s a big time saver versus roasting it!
Roasted spaghetti squash
Here’s the trick to how to cook spaghetti squash

How to cut spaghetti squash

What involves the most technique in this spaghetti squash casserole? Cutting the squash! Our trick for getting the longest noddles is to cut the squash in half width-wise instead of lengthwise. The strands of the squash actually run around the width of the squash, not the length. It’s also easier to cut this way so the knife doesn’t slip. Here are the basic steps of how to cut a spaghetti squash (and see the video below!):

  1. Find a small sharp paring knife. This sounds counter-intuitive! But it’s the safest method because it helps to prevent the slippage that can happen with a large knife.
  2. Cut the squash around the middle, width-wise. To cut, pierce the knife into the squash and swing down, making small slices around the squash until it breaks in half. This makes the longest strands or “noodles”.
  3. Remove the seeds. Use the knife to cut around the seeds, then scoop out the seeds with a spoon.

Ways to make it a meal!

This spaghetti squash casserole can be served as a main dish or a side dish. As we mentioned above, with the prep time (1 hour 30 minutes) we’d use it as a side for entertaining. To make it into a vegetarian dinner recipe, here are a few side dishes you could pair with it!

Spaghetti squash casserole

This spaghetti squash casserole recipe is…

Vegetarian and gluten-free.

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Spaghetti squash casserole

Spaghetti Squash Casserole

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  • Author: Sonja Overhiser
  • Prep Time: 20 minutes
  • Cook Time: 1 hour 5 minutes
  • Total Time: 1 hour 25 minutes
  • Yield: 8 as a side, 4 as a main 1x
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This cheesy baked spaghetti squash casserole is a winner! It stars Italian style flavors: pesto, artichoke, mozzarella, and Parmesan cheese.


  • 1 medium spaghetti squash
  • 1 teaspoon olive oil
  • 2 cups baby spinach
  • 1 14-ounce can quartered artichoke hearts, chopped
  • ¼ cup sun dried tomatoes, chopped
  • ¼ cup basil pesto
  • 1 teaspoon kosher salt
  • 4 ounces fresh mozzarella, torn into pieces
  • ½ cup grated Parmesan cheese,  plus additional for sprinkling


  1. Cook the spaghetti squash: Roasted Spaghetti Squash (takes about 1 hour total) or Instant Pot Spaghetti Squash (takes 30 minutes total). You can cook the spaghetti squash in advance and refrigerate until preparing: just bake it longer in the final step until fully warmed through.
  2. Let the spaghetti squash drain for 10 minutes, as instructed in the cooking method above. (This makes sure that the casserole does not have extra liquid.)
  3. Preheat the oven to 400 degrees Fahrenheit (if not already roasting the squash).
  4. While the spaghetti squash cooks, roughly chop the spinach, artichoke hearts, and sun dried tomatoes.
  5. In a large bowl, combine the warm squash strands, spinach, artichokes, sun dried tomatoes, pesto, salt, mozzarella, and the Parmesan cheese. Stir until thoroughly combined and transfer to a medium casserole dish. Sprinkle the top with additional Parmesan cheese. Bake at 10 to 12 minutes until the mozzarella cheese is melted. Serve immediately.
  • Category: Side Dish
  • Method: Baked
  • Cuisine: Italian Inspired

About the authors

Sonja & Alex

Hi, we’re Alex and Sonja Overhiser, married cookbook authors, food bloggers, and recipe developers. We founded A Couple Cooks to share fresh, seasonal recipes and the joy of cooking! Our recipes are made by two real people and work every time.

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