The word is derived from the Latin word pica, meaning magpie:
Magpies and crows are well-known for their habit of collecting an assortment of odds and ends in their nests. Not so very different, the thinking goes, from the way medieval cooks assembled ingredients for their pies.
It's a triple layer cake with a pie baked into each layer. To make the bottom layer, you bake an entire apple pie inside a spice cake. The middle layer is a pumpkin pie baked inside a yellow cake. Top it off with a cherry pie baked inside of a white cake. Once finished and frosted, it's a foot tall and packs an astronomical number of calories per slice. Diabetics and health-food devotees will run screaming.