Preheat your oven to 400°F. Line a baking sheet with parchment paper.
In a large bowl, combine the ground beef, breadcrumbs, Parmesan cheese, parsley, milk, egg, garlic, onion powder, Italian seasoning, salt, and black pepper. Mix until just combined; do not overmix.
Using your hands, form the mixture into meatballs, about 1 to 1.5 inches in diameter. Place the meatballs on the prepared baking sheet, spaced evenly apart.
Bake in the preheated oven for 18-20 minutes, or until the meatballs are cooked through and browned on the outside.
Serve the meatballs warm with marinara sauce for dipping or over pasta.