Here is the over-the-hill cake I did for a friend's mom's birthday party. The bottom tier is krispy treat & the top two cakes are pumpkin with rum buttercream filling.
Four batches of rice krispy treats (12-inch bottom layer), three cake mixes, three batches butter cream icing, two batches marshmallow fondant, and a lot of blood (well, not really - gross), sweat, and (almost) tears later, here it is!