Preheat your oven to 400°F (200°C) and prepare a baking sheet lined with parchment paper.
In a mixing bowl, combine the ground beef, breadcrumbs, grated Parmesan cheese, milk, minced garlic, egg, Italian seasoning, salt, and pepper. Mix until just combined.
Form the mixture into meatballs, about 1 inch in diameter, and place them on the prepared baking sheet.
Bake the meatballs in the preheated oven for about 20 minutes or until cooked through and browned.
While the meatballs are baking, cook the pasta according to package directions in a large pot of salted boiling water. Reserve ½ cup of pasta water, then drain the pasta.
In a large skillet, melt the butter over medium heat. Add the minced garlic and sauté until fragrant, about 1-2 minutes. If desired, add red pepper flakes for some heat.
Add the cooked meatballs to the skillet and coat them in the garlic butter sauce.
In the same pot used for the pasta, add the heavy cream, grated Parmesan cheese, and season with salt and pepper. Stir until well combined and heated through.
Toss the cooked pasta with the creamy sauce, adding reserved pasta water as needed to reach desired consistency.
Serve the creamy pasta topped with the garlic butter meatballs and garnish with fresh parsley.