Spaghetti Squash Casserole

This spaghetti squash casserole delivers on every front. It’s hearty and nutritious thanks to a medley of vegetables, lean ground beef and the star of our dish: spaghetti squash. Each bite of this casserole is pure comfort! It’s one of our popular spaghetti squash recipes and a low-carb comfort food that works as both a main and a side. And if you’ve been hunting for freezer meal recipes, this spaghetti squash casserole recipe hits all the right notes.

Ingredients for a Spaghetti Squash Casserole

• Spaghetti squash: This winter squash has a nutty, slightly sweet flavor. When cooked, the flesh separates into spaghetti-like strands.
• Beef: Lean ground beef is the king of casseroles. Look for ground beef with around 10 to 15% fat.
• Vegetables and garlic: Onions, red pepper, tomatoes and garlic lend fragrant aromas and punchy flavors. Use the juice from the canned tomatoes too—it will prevent the casserole from drying out.
• Dried oregano: This herb adds an aromatic, slightly peppery flavor. Feel free to mix in additional herbs and spices (I use an Italian seasoning).
• Shredded cheese: Shred the cheese yourself. Pre-shredded cheese won’t melt quite as well in the oven.
• Parsley: Brighten the spaghetti squash casserole recipe with a pop of color from fresh parsley.

Directions

Step 1: Bake the squash

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Preheat the oven to 375°F. Cut the squash in half lengthwise and scoop out the seeds.

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Place the squash cut side down in a baking dish and add water.

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Cover and bake for 20 to 30 minutes or until the squash is easily pierced with a fork. Remove the squash from the oven.

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Once the squash is cool enough to handle, scoop out the strands and separate them with a fork. Lower the oven temperature to 350°.

Step 2: Saute the beef and vegetables

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In a skillet, saute the beef, onion, red pepper and garlic until the meat is browned and the vegetables are tender, five to seven minutes. Then, drain the grease.

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Stir in the tomatoes, oregano, salt, pepper and squash. Cook and stir until the liquid is absorbed, another one to two minutes.

Step 3: Bake the casserole

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Transfer the contents of the skillet to an ungreased 1-1/2-quart baking dish. Bake, uncovered, for 25 minutes. Remove the casserole from the oven, then garnish the top with cheese and fresh parsley. Let the casserole rest for a few minutes before slicing and serving.

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Spaghetti Squash Casserole Variations

• Switch up the protein: Use ground turkey, shredded rotisserie chicken, chopped bacon or pulled pork to change up the spaghetti squash casserole recipe. Of course, you can leave all that out to make a tasty vegetarian casserole.
• Try a different cheese: Mozzarella and cheddar lean toward the milder side, so swap the cheese to liven up this recipe. Use smoked Gouda, Monterey Jack, extra sharp cheddar or Parmesan.
• Mix in extra vegetables: Toss in chopped broccoli florets, bell pepper, zucchini or corn. For a meatless spaghetti squash casserole, adding more vegetables brings extra heartiness to the dish.
• Turn up the heat: Stir in chopped hot peppers, a dash of red pepper flakes or a splash of hot sauce for a kick.

How to Store Spaghetti Squash Casserole

Let the casserole cool, then wrap the dish well in foil and store in the refrigerator.

How long does spaghetti squash casserole last?

When refrigerated, the casserole should last three to four days.

Can you freeze spaghetti squash casserole?

Yes! If freezing it from baked, let the casserole cool completely, then wrap the whole dish tightly in foil or storage wrap. Your frozen spaghetti squash casserole will last about three months.

How do you reheat spaghetti squash casserole?

If you’re reheating a baked casserole from frozen, let the casserole thaw in the fridge overnight. For a quick reheat, pop a portion in the microwave and warm it on high until heated through. Otherwise, reheat the casserole in the oven at 350° for 15 to 20 minutes. When cooking an unbaked spaghetti squash from frozen, bake at 375° for 40 to 45 minutes.

Can you make spaghetti squash casserole ahead of time?

To make the casserole ahead, cook all the components and assemble the dish. Wrap the casserole well and store it in the refrigerator for up to two days or in the freezer for up to three months.

Spaghetti Squash Casserole Tips

How do you pick a good spaghetti squash?

When browsing the produce aisle, look for a vibrant orange-gold squash that’s spot and blemish-free, without any visible cracks. A ripe spaghetti squash feels heavy and should be firm rather than soft.

How else can you cook spaghetti squash for a casserole?

Spaghetti squash can be cooked in the microwave (the fast option) or a slow cooker. If going the ‘wave route, arrange the squash on a microwave-safe plate cut side down. Microwave on high until the halves are tender, about 15 minutes. For the more leisurely method, put the squash cut side down in a 5- to 7-quart slow cooker. Secure the lid and cook on low for four to six hours.

What can you serve with spaghetti squash casserole?

The combination of flavors in this spaghetti squash casserole recipe means it’s delicious with a host of sides. I think lighter sides like a fresh green salad, lemon almond asparagus or sauteed zucchini are stellar, but a plate of warm garlic knots or pull-apart herb bread will round out the meal too.