HEAT oven to 350°F. Coat 13 x 9-inch baking pan with baking spray. Prepare cake mix according to package directions using water, oil and eggs. Spread evenly in prepared pan. Bake according to package directions. Cool completely in pan on wire rack.
CRUMBLE cooled cake into extra-large bowl. Beat with electric mixer on medium speed until fine crumbs, about 2 minutes. Spoon frosting over cake crumbs. Beat until evenly blended. Cover and freeze 30 minutes.
LINE 15 x 10-inch baking pan with wax paper. Roll cake mixture into 1 1/2-inch balls. Place on prepared baking pan. Insert sticks. Cover and freeze at least 1 hour.
REMOVE a few cake balls from freezer at a time, keeping the rest frozen. Shake topping. Pour into small bowl. Dip cake balls in topping to coat, allowing excess to drip off. Immediately sprinkle with a few candy bits from frosting container or other decorator sprinkles. Repeat with remaining cake balls. Freeze until coating is hardened. Store in freezer.