HEAT oven to 350°F. Coat 13 x 9-inch baking pan with baking spray. Prepare cake mix according to package directions using the 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 a 15 x 10 x 1-inch baking pan with wax paper. Roll cake mixture into 1 1/2-inch round balls or bites. Place on wax paper. Cover and freeze at least 1 hour.
COMBINE chocolate chips and shortening in medium microwave-safe bowl. Microwave on HIGH 2 minutes; stir. Microwave at additional 10 second intervals until completely melted and smooth when stirred.
REMOVE a few cake bites from freezer, keeping the rest frozen. Drop bites into coating mixture. Using a spoon, cover bites with coating, without stirring the bites in coating. Lift each bite with fork, allowing access coating to drip off into bowl. Using toothpick, gently push bite off fork onto wax paper. Immediately sprinkle with decorator sprinkles. Repeat to coat remaining cake bites. (If coating thickens, microwave at additional 10 second intervals until desired consistency when stirred.) When complete, chill 5 minutes or until coating is set. Serve at room temperature.
TIP: To prepare 1 dozen cake bites, prepare cake according to above directions, but use only one-fourth of prepared cake. Reserve remaining cake for another use. Use only 3 tablespoons frosting, 1 1/2 cups chocolate chips and 2 tablespoons shortening when making cake bites.