Preheat your oven to 400°F (200°C) and prepare a baking sheet by lining it with parchment paper or lightly greasing it.
In a large mixing bowl, combine the ground beef, breadcrumbs, grated Parmesan cheese, milk, egg, garlic powder, onion powder, Italian seasoning, salt, and pepper. Mix thoroughly until all ingredients are well incorporated.
Take a small amount of the meat mixture and flatten it in your hand. Place about 1 tablespoon of shredded mozzarella cheese in the center, then mold the meat around the cheese to form a ball.
Repeat the process of forming meatballs until all the meat mixture is used.
Place the formed meatballs on the prepared baking sheet, spacing them apart.
Bake in the preheated oven for 20-25 minutes, or until cooked through (internal temperature should reach 165°F or 74°C).
If desired, in the last few minutes of baking, you can broil the meatballs to achieve a golden top by switching the oven to broil mode.
Serve hot with marinara sauce, if desired.