In a large mixing bowl, combine the ground beef, breadcrumbs, Parmesan cheese, parsley, milk, egg, garlic powder, onion powder, salt, and black pepper. Mix until well combined.
Shape the mixture into small meatballs, about 1 inch in diameter. You should have approximately 24 meatballs.
If desired, bake the meatballs in a preheated oven at 400°F (200°C) for 20 minutes to brown them slightly. This step is optional but adds extra flavor.
In the crockpot, combine the cranberry sauce, barbecue sauce, and soy sauce. Stir until well mixed.
Add the meatballs to the crockpot, making sure they are evenly coated with the sauce.
Cover and cook on low heat for 4 hours or on high heat for 2 hours, until the meatballs are cooked through and tender.
Once cooked, serve hot with additional sauce spooned over the top.