CHOCOLATE CHERRY CAKE:
Prepare cake as directed above, except stir 1/2 cup coarsely chopped, well-drained maraschino cherries into the batter at the end of Step 2. To assemble, place one cake layer on a serving plate, top side up. Spread with 1 cup of the Chocolate Butter Frosting. Snip any large cherry pieces in 1/2 cup cherry preserves. Spread preserves on top of frosting on first cake layer, leaving a 1-inch space around the top edges of the cake. Top with second cake layer, top side up. Use the remaining Chocolate Butter Frosting to frost the top and sides of the whole cake. If desired, garnish the top of the cake with well-drained whole maraschino cherries.