Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.

In a mixing bowl, combine Italian bread crumbs with a splash of milk. Let sit for 5 minutes.

Add ground beef, diced onion, minced garlic, beaten egg, salt, black pepper, parmesan cheese, and parsley. Mix gently until just combined.

With wet hands, scoop and shape the mixture into 2-inch meatballs and place them on the prepared baking sheet.

Bake for 18-20 minutes until they reach an internal temperature of 165°F (74°C) and are golden brown.

Remove from oven, drain excess fat, and serve hot with marinara sauce, in a sub, or alone.