In medium microwavable bowl, microwave 1 bag of candy melts uncovered on Medium (50%) 1 minute, then in 15-second increments, until melted; stir until smooth. Remove several cake balls from refrigerator at a time. Dip cake balls into melted candy to cover; tap off excess. Place on cooking parchment paper. Immediately sprinkle with some of the remaining 1/2 cup sprinkles. Let stand until set. Repeat with remaining bag of candy melts, cake balls and sprinkles.