Preheat oven to 400°F (200°C). Line a baking sheet with parchment paper.

In a large bowl, combine ground beef, breadcrumbs, Parmesan cheese, egg, garlic, Italian seasoning, salt, and pepper. Mix gently until just combined.

Roll the mixture into 1-inch meatballs and place them on the prepared baking sheet.

Bake for 20-25 minutes, or until cooked through.

While meatballs are baking, cook pasta according to package directions.

In a large skillet, melt butter over medium heat. Add garlic and cook for 1 minute, or until fragrant.

Add spinach and cook until wilted.

Stir in heavy cream, Parmesan cheese, salt, and pepper. Bring to a simmer and cook for 5 minutes, or until the sauce has thickened slightly.

Drain pasta and add it to the skillet with the spinach sauce. Toss to coat.

Add the baked meatballs to the pasta and sauce. Toss gently to combine.

Serve immediately and garnish with extra Parmesan cheese, if desired.