STEP ONEPREPARE cake mix according to package directions using the water, oil and egg whites to make 1 (8-inch) cake layer. Cool completely.
STEP TWOCRUMBLE cooled cake into large bowl. Beat with mixer on medium speed until fine crumbs, about 2 minutes. Spoon frosting over cake crumbs. Beat until evenly blended. Cover and freeze 30 minutes.
STEP THREELINE bottom of 13 x 9-inch baking pan with wax paper. Roll cake mixture into 1 1/4-inch balls. Insert lollipop stick into center of each ball. Place on wax paper. Cover and freeze at least 1 hour.
STEP FOURPLACE candy bits from frosting and other decorator sprinkles in small bowls. Line baking sheet with wax paper. Microwave baking chips and shortening in medium microwave-safe bowl on HIGH 1 minute; stir. Microwave at additional 10 second intervals until completely melted and smooth when stirred. Stir in peppermint extract until blended.
STEP FIVEREMOVE cake pops from freezer. Hold one pop over bowl of coating. Working quickly, spoon coating over cake pop, turning to cover completely. Let excess coating drip off into bowl. Immediately sprinkle with candy bits from frosting or other decorator sprinkles, if desired. Stand upright on wax paper. Repeat to make additional cake pops. As coating thickens, microwave at additional 10 second intervals until desired consistency when stirred. Chill when complete. Serve at room temperature.