Meatball Stuffed Spaghetti Squash

1 . Stage

Preheat the oven to 400° with a rack in the upper and lower third. Cut spaghetti squash in half lengthwise and scoop out seeds. Drizzle with 2 tablespoons of the olive oil and season with salt and pepper. Place cut side down on a large baking sheet and roast on the bottom rack until flesh is easily shreddable, about 40 minutes. 

2 . Stage

Meanwhile, make the meatballs: grease a large baking sheet with cooking spray. In a large bowl, combine beef with bread crumbs, parsley, Parmesan, egg, 1 minced garlic clove, 1 teaspoon salt, and a few pinches of red pepper flakes. Roll mixture into 16 meatballs and place on prepared baking sheet. Bake on the upper rack, until golden and cooked through, about 15 minutes.  

3 . Stage

Meanwhile, in a large skillet, heat the remaining 2 tablespoons of oil over medium-high. Add onion and cook, stirring, until soft, about 5 minutes. Add the remaining garlic and cook, stirring, until fragrant, about 30 seconds. Pour in the crushed tomatoes and add a few pinches of red pepper flakes. Simmer until sauce has thickened, about 10 minutes. Season with salt and pepper. 

4 . Stage

Heat broiler on high. Shred spaghetti squash into strands with a fork. Spoon meatballs and sauce into squash. Stir and top with mozzarella cheese. Broil until golden. 

5 . Stage

Garnish with basil and serve.