Prepare Chocolate Cake Mix according to bag directions. Scale 1 pound 8 ounces into sprayed 8-inch cake pans. Bake at 350°F until cake springs back lightly when touched in the center. Let cool completely and depan. Build 3-layer cake with prepared cake layers and white buttercreme, crumb coat, use internal dowels for support, and place in cooler to set up. Using 5 small mixing bowls, place varying amounts of blue buttercreme in each of the bowls, starting with lots of blue and ending with no buttercreme so that each bowl has less and less. Working from the opposite direction, place white buttercreme in the bowls. Mix buttercremes, adjust if necessary to make sure that each hue is unique. Using a paring knife, mark the cake roughly into 5 even stripes. At the base of the cake, pipe the darkest blue buttercreme with a large plain straight tip. Repeat with each color, going darkest to lightest, ending with white buttercreme by the top edge of the cake. Swirl the design with a palette knife.
This cake can also be made with Dawn Exceptional Baker's Request Devil's Food Cake Mix (00495128).
Chocolate, Cleaner Ingredients, Blue, Buttercreme, Buttercream, Layer Cake