In a large bowl, combine ground meat, egg, breadcrumbs, Parmesan, parsley, garlic, salt, and pepper. Mix until just combined and form into 1-inch balls. Set aside.

Heat olive oil in a skillet over medium heat. Add meatballs in batches and brown on all sides for 6–8 minutes. Remove and set aside.

In the same skillet, add butter, garlic, and red pepper flakes. Cook for 1–2 minutes until fragrant. Stir in lemon juice and remaining parsley. Return meatballs to the skillet and simmer on low for 5–7 minutes.

Cook linguine according to package directions. Reserve ½ cup pasta water. In a saucepan, melt butter, add heavy cream, and bring to a gentle simmer. Stir in Parmesan until melted. Thin with pasta water if needed. Toss cooked linguine in the sauce.

Serve meatballs over creamy linguine, drizzle with extra garlic butter, and garnish with parsley and Parmesan.