In a large bowl, combine ground beef, ground pork, breadcrumbs, Parmesan cheese, egg, oregano, garlic powder, salt, and pepper. Gently mix until just combined.
Roll the meat mixture into 1-inch meatballs.
Place meatballs on a baking sheet lined with parchment paper.
Bake for 20-25 minutes, or until cooked through.
Serve immediately with marinara sauce and mozzarella cheese.
Notes
These meatballs can be made ahead of time and reheated. Store leftovers in an airtight container in the refrigerator for up to 3 days.