Place the chocolate cake onto a serving plate, this will be the base cake. Make a cavity in which to hold the sweets by taking an oversized mug to hollow out a circular area, taking care not to go all the way through to the the plate. Before placing the red velvet cake on top, repeat this process to make the top of the cavity, only removing a small amount of cake so that the cake does not collapse when decorated, nor reveal the cavity.
Spoon some vanilla frosting onto half of the lower level cake, and the chocolate frosting around the other half. Fill the hole, and more to be heaping, with (unwrapped) sweets then place the second cake layer on top matching up the cavity over the sweets.
Finish off using the chocolate icing on the opposite side of centre filling and the same with the vanilla so you get a taste of both creams. Decorate with jelly beans or other sweets.
Sweets can be anything of your choice: M&M's®, Mintstrels®, Skittles®, Smarties®, Jellybeans®.
To make the cakes you can use a cake mix or a recipe, either would work fine.