Students learn about geologic sampling by taking 'core samples' from a layer cake. The activity gives specific directions on how to prepare the Earth cake, complete with raisin, pecan and chocolate chip fossils. Students use a rolled-up transparency film tube to carefully remove a core sample and observe the sediment layers and any fossils embedded in the sediment layers. At the end of the activity, a foil covering is taken off of the sides of the cake so that the students can observe the changes in sedimentary layers.