Preheat oven to 400 degrees F (200 degrees C) and line a rimmed baking sheet with parchment paper or a silicone mat.
In a large mixing bowl, combine breadcrumbs, Parmesan, egg, milk, garlic, oregano, salt, and pepper. Allow the mixture to stand for 5 minutes to hydrate the panade.
Add the ground beef and parsley to the bowl. Mix gently by hand until the ingredients are just incorporated, being careful not to overwork the meat.
Shape the mixture into 1.5-inch spheres, approximately 2 tablespoons each, and place them on the prepared baking sheet spaced 1 inch apart.
Bake for 18 to 22 minutes or until the internal temperature reaches 165 degrees F (74 degrees C) and the surfaces are evenly browned.
Remove from oven and allow the meatballs to rest for 5 minutes before serving or adding to sauce.