Its one cake that is then cut into layers. The lighter color at the bottom is an indication of its rise. The pan is covered in butter and flour before the batter is added. As it rises, it pushes up that flour from the pan. Kind of a high water mark. The pattern on the top is just from a folded up piece of parchment paper that is placed in the bottom of the pan to ensure it releases easily. The pattern is the folds in the paper before its cut to fit the pan. You butter the whole pan. The paper goes in. You butter the paper. Then its all dusted with flour.