I know it's not the first time that a layer cake has been used as an analogy for stratigraphy, but what about tectonic-stratigraphic relationships? I couldn't help but notice that the cake that showed up at our last historical geology class had some extra geological complications: I'm pretty sure we have an ocean-continent convergent boundary, complete with a magmatic arc on the right, a yellow forearc basin in the middle (representing our own local geological environment), and an accretionary wedge made up with a melange of candy sprinkles. The chaotic nature of the accretionary wedge became more apparent when we had to carve and serve the cake with little plastic spoons!
If you want to argue about the exact placement or angles of the various elements I'm describing, I challenge you to cook up and post something better! Thanks to Melissa for the cake, and Erricka for the picture!