Preheat oven to 375ºF. Lightly grease 9x13-inch baking dish with cooking spray.
In large bowl mix ham, pork, eggs, milk, graham cracker crumbs, onion powder, and garlic powder until well combined.
Roll the meat mixture into approximately 3-inch round balls and place in baking dish.
In a small bowl combine ketchup, brown sugar, apple cider vinegar, and ground mustard.
Pour ketchup mixture evenly over ham balls.
Bake for 45-50 minutes. Ham balls should reach an internal temp of at least 160º F.