Bake the cake according to package directions. Let cool completely, then crumble the cake into a large bowl. Mix cake crumbs with frosting until it can be formed into balls that hold together. The dough should not be sticky, so you may not need all of the frosting.

Form into balls and place on a cookie sheet lined with wax paper. Refrigerate cake balls for a few hours.

Dip cake balls into melted chocolate and decorate with sprinkles.