Classic Black and White Cookie vs Eierkuchen (German Pancakes)

Both dishes lean on milk, sugar, butter and egg, but they put them to very different work. The black and white cookie creams butter with sugar, lifts the dough with baking powder and bakes it into a soft-set round, then tops it with a simple powdered-sugar glaze, half vanilla and half cocoa. Eierkuchen uses no leavening: a thin, rested batter of flour, egg and milk is fried in butter until golden with slightly crisp edges. One is sweet and frosted; the other is mildly sweet, finished at the table with sugar or jam.