Place rack in top third of oven; preheat to 425°F. Lightly brush a large rimmed baking sheet with olive oil or line with parchment paper for easier clean up.

In a large bowl, combine bread crumbs and milk, tossing and pressing with a fork to ensure all the bread is coated in milk. Let soak for 5 to 10 minutes.

Add the egg, egg yolk, garlic, parmesan, parsley, salt, and pepper to the soaked bread crumb mixture. Use a fork to mix everything together well.

Mix in half of the ground beef and pork and use your hands or a large spoon to gently combine. Don't overmix. Add remaining ground meat and mix well to thoroughly combine without overworking it too much. (Adding the meat in batches allows for easier mixing without overworking the mixture).

Rub your hands with a bit of olive oil and shape mixture into golf-sized balls (about 2-inch diameter). Place on prepared baking sheet.

Bake for about 20 minutes, or until the meatballs have reached an internal temperature of 165˚F. Remove from oven and drain off any excess fat.

To finish cooking meatballs in a tomato sauce: Bake meatballs for only 12 to 15 minutes. Place in heated tomato sauce and simmer until meatballs are just cooked through, about 10-12 minutes, or until an internal temperature registers 165˚F.