Coat the inside of the crock pot with non-stick cooking spray. Set aside.
In a large mixing bowl, combine the ground beef, ground pork, panko, parmesan, parsley, milk, Italian seasoning, salt, garlic powder, and eggs until evenly mixed.
Use a large cookie scoop (or a 1-tablespoon measuring spoon) to scoop 3-tablespoon portions of the meatball mixture. Roll each scoop into a ball. Place the meatballs in the bottom of the prepared crockpot.
Pour the marinara sauce over the meatballs. Cover and cook on HIGH for 2.5 hours or until the meatballs are cooked through.
Serve over cooked pasta topped with shredded parmesan and chopped parsley. You can also turn the crockpot to WARM and serve the meatballs with toothpicks for a party appetizer.