These little cakes are quite famous in Germany as well. In the US they are known as "black-and-white cookie" - I guess therefore in Germany we simply call them "Amerikaner". The topping that we do in Germany is commonly done with lemon flavour.
flour, sugar, butter, buttermilk,baking powder, Bi-Carb, salt, vanilla paste,egg (base)
Icing sugar, lemon (glaze)