I did a joke cake at work one day. I took foam, like foam bought at a hobby shop for seat cushions, and glued them together. I traced around a cake pan and cut the foam. Then I glued it to a cake board. I then put chocolate frosting on it and decorated it real nice. The frosting smelled wonderful, so they taste buds watered when you smelled the "cake". I placed a butter knife by the cake. It is a hoot to see people try to cut it. They can't cut it with a butter knife.