Prepare cake according to package directions, using the eggs, butter, and can of cherry soda. Bake in 3 8" cake pans. Cool completely according to directions on cake mix.
Place 1 layer on cake serving plate. Pipe a ring around the outside top of the layer about 1 1/2 inches wide and 1 inch high with the whipped cream. Spoon 1/3 of the cherry pie filling inside the ring.
Place second layer on top of the first layer, and complete as above.
Place third layer on very top. This time Pipe the whipped cream all over the top, making it shallower in the center. Spoon the remaining pie filling in the center of the top of the cake. Decorate with chocolate shavings if desired.