1 HR 32 MIN
Heat oven to 350ºF.
Prepare cake batter and bake as directed on package for 13x9-inch cake, blending dry pudding mix into batter before pouring into prepared pan. Cool completely.
Use pulsing action of food processor to process cake, in batches, until fine crumbs form. Place crumbs in large bowl. Add small amount of frosting; mix well with your hands. Mix in remaining frosting; roll into 40 (1-inch) balls.
Cover baking sheet with parchment. Melt white chocolate in microwave as directed on package. Dip end of 1 lollipop stick into melted chocolate, then insert coated end halfway into 1 cake ball. Place on prepared baking sheet. Repeat with 19 additional lollipop sticks and 19 of the remaining cake balls. Dip balls, 1 at a time, in remaining melted chocolate; gently shake coated ball over bowl of melted chocolate to remove excess chocolate before returning cake ball to prepared baking sheet.
Repeat with semi-sweet chocolate and remaining cake balls. Let stand 45 min. or until chocolate is firm.