This recipe for Classic Baked Spaghetti Squash with Meat Sauce has been a go-to in my kitchen for cozy weeknights and casual Sunday dinners. I first developed this version when I wanted all the comforting flavors of baked pasta but without the heavy carbs. Spaghetti squash gives that stringy, pasta-like texture while keeping the dish light and bright. The combination of browned lean beef, a seasoned tomato sauce, and a generous blanket of mozzarella brings a familiar, satisfying finish that our family reaches for again and again.

I discovered the magic of turning spaghetti squash into a sturdy edible bowl during a winter meal prep session. Roasting the squash until the strands separate cleanly makes assembling and serving simple, and stuffing each half with cheese and beef creates a presentable dish that feels special even on ordinary nights. The texture is tender but slightly toothsome, the cheese gets bubbling and golden, and the tomato sauce adds that comforting acidity that balances the richness. This is the meal I bring to potlucks and the one my kids always ask to take for school lunches the next day.

Ingredients

• Spaghetti squash: Use 2 medium squash, about 2 to 3 pounds total. Look for firm skins with no soft spots and even color. Medium squash cooks evenly and fits on a standard baking sheet. If you can find organic produce, it can add a slightly sweeter note.
• Mozzarella cheese: 1 cup shredded plus extra for topping. Whole-milk mozzarella melts best and gives that lovely pull. Pre-shredded works in a pinch but for best melt and texture buy a block and shred it yourself.
• Parmesan cheese: 1/2 cup shredded. A real Parmigiano-Reggiano adds a nutty saltiness that brightens the filling. Finely grate for even distribution.
• Lean ground beef: 1 pound. Choose 90/10 or 93/7 for a balance of flavor and lower grease. If you prefer, ground turkey or a plant-based crumble can substitute.
• Onion and garlic: One small onion diced and 2 teaspoons minced garlic. Yellow or sweet onion gives a good savory base. Fresh garlic is best for aroma and depth.
• Spaghetti sauce: 24 ounces jarred tomato sauce. Choose a style you love plain or seasoned. For lower sugar and carbs, use a no-sugar-added or low-carb marinara.
• Salt and pepper: Season to taste. Kosher salt and freshly cracked black pepper work best for balanced seasoning.

Instructions

Preheat and prepare the squash:Preheat the oven to 375°F. Line a baking sheet with parchment or lightly oil it. Cut each spaghetti squash lengthwise and scoop out seeds. Place the halves cut side down on the sheet. Roast for 45 to 50 minutes until the flesh is tender and a fork slides easily through. The skin should be slightly browned at the edges. Roasting time varies with size; test by piercing the flesh.Shred the squash:Let the squash cool enough to handle. Use a fork to scrape the flesh into spaghetti-like strands, keeping each half intact if you plan to use the shells for serving. Transfer the strands to a large bowl and set the empty shells back on the baking sheet for later stuffing.Brown the meat:Heat a skillet over medium-high and add the ground beef, diced onion, and minced garlic. Cook until the beef is well browned and the onion is translucent, about 7 to 9 minutes. Drain any excess fat and return the meat to the pan. Add the 24-ounce jar of spaghetti sauce and let the mixture simmer for 3 to 5 minutes to meld flavors. Taste and adjust salt and pepper.Mix the cheesy filling:To the bowl of squash strands add 1 cup shredded mozzarella, 1/2 cup shredded Parmesan, and salt and pepper to taste. Mix gently but thoroughly so the cheese distributes and the strands are coated. The mixture should hold together slightly when pressed.Assemble the boats:Divide the cheesy squash evenly among the four empty squash shells. Spoon the meat sauce over each filled shell. Top each boat with extra shredded mozzarella for a bubbly finish. For a golden top, heap a generous handful of cheese on each half.Bake and finish:Return the assembled boats to the oven and bake at 375°F for about 10 minutes or until the cheese melts and begins to brown at the edges. Switch to broil for a minute if you want a deeper color, watching closely to prevent burning. Let the boats rest for 5 minutes before serving so the filling sets slightly.

Storage Tips

Store cooled leftovers in airtight containers in the refrigerator for up to four days. To freeze, cool completely, wrap each filled half tightly in plastic wrap then foil, and place in a freezer-safe bag for up to three months. When reheating from frozen, thaw overnight in the refrigerator and reheat in a 350°F oven until warmed through, about 20 to 30 minutes. Glass containers with tight lids work well for fridge storage while aluminum pans are convenient for freezing and reheating directly.

Ingredient Substitutions

If you want to reduce red meat, swap 1 pound lean ground beef for 1 pound ground turkey or chicken; increase seasonings slightly for depth. For a vegetarian option, use a cup of cooked lentils plus sautéed mushrooms in place of meat—lentils provide protein and a meaty texture. Swap mozzarella for a dairy-free shredded cheese if needed and choose a tomato sauce without added sugar for a lower-carb version. Adjust salt gradually when swapping cheeses since Parmesan is quite salty.

Serving Suggestions

Serve each squash boat with a crisp green salad dressed lightly with lemon vinaigrette to cut through the richness. A side of roasted vegetables such as asparagus or Brussels sprouts pairs nicely. Garnish with fresh basil leaves and a sprinkle of extra Parmesan for color and brightness. For a family-style meal, present whole halves on a large platter so everyone can help themselves and add individual hot sauce or chili flakes at the table.

Cultural Background

This approach blends a classic Italian-American love of baked pasta with a modern vegetable-forward twist. Spaghetti squash is native to Central and South America but gained popularity in contemporary American cooking as a pasta substitute. The idea of stuffing vegetables with savory mixtures resembles Mediterranean stuffed vegetable traditions. Combining rich cheeses, tomato-based sauce, and browned meat follows the comfort-food lineage of classic casseroles while honoring a lighter, seasonal vegetable base.

Seasonal Adaptations

In summer, swap the jarred sauce for crushed fresh tomatoes, basil, and a splash of olive oil to create a brighter tomato profile. In autumn, add a pinch of nutmeg and a few tablespoons of roasted butternut squash puree to the filling for a warmer, autumnal note. During winter holidays, top with a mix of provolone and sharp cheddar for a deeper melt and serve with roasted root vegetables and a hearty red wine.

Meal Prep Tips

To save time, roast several squash up to two days ahead and store the strands in the refrigerator. Prepare the meat sauce and keep it in a sealed container; reheat gently before assembling. When assembling multiple portions, fill the shells and cool before covering and refrigerating; bake just before serving. Use portion-sized foil containers for freezing individual servings so reheating is quick and convenient on busy nights.

This dish brings together comfort, practicality, and flexibility. Whether you are cooking for a family of four or preparing meals for the week, these stuffed squash halves are a satisfying, lower-carb alternative to traditional baked pasta that invites personalization and makes weeknight dinners feel just a bit more special.