Heat the oven to 350 F and line a large rimmed baking sheet with foil. Oil the foil or spray it with cooking spray.
Combine the ground beef, minced garlic, Parmesan cheese, egg, breadcrumbs, milk, Italian seasoning, salt, garlic powder, and pepper in a large bowl. Mix until the ingredients are well combined. Divide the meat mixture into 16 to 18 pieces, roughly 1.5 to 1.6 ounces each.
Wrap each portion of meat around a ball of mozzarella cheese and shape it into a meatball. Make sure the cheese is well-wrapped and sealed.
Arrange the meatballs in the baking pan and bake for 30 minutes, or until thoroughly cooked. If you check with an instant-read thermometer, look for an internal temperature of 160 F.
Serve the meatballs warm as an appetizer with marinara or pizza sauce on the side, or toss them in hot marinara sauce and serve over pasta for a satisfying family dinner.