Preheat your oven to 400°F (200°C).
Line a baking sheet with parchment paper.
In a large bowl, combine ground beef, breadcrumbs, egg, Parmesan cheese, onion, garlic, Italian seasoning, salt, pepper, Worcestershire sauce, and milk (if using).
Mix gently with your hands or a spoon until just combined.
Scoop out about 1 tablespoon of the mixture and roll it into a ball.
Repeat with the remaining mixture, placing the meatballs evenly on the baking sheet.
Bake for 18–20 minutes, or until the meatballs are cooked through (internal temperature of 165°F/75°C).
Enjoy with your favorite sauce and side dishes!