Mix the butter, sugar and spices until frothy. Sift the flour, cornstarch and baking powder. Eggs and flour are stirred alternately with speed 1 below.
Line the loaf pan (approx. 25/10/7 cm) with sandwich paper. Pour in half the mixture and pull it up a little at the edge. Color the 2nd part with cocoa and milk and fill into the hollow.
Bake at approx. 160 ° C for 45 minutes. If the cake has a small skin (after approx. 10 minutes), carefully cut into it with a sharp knife so that the cake can rise evenly. Cover with chocolate icing if necessary.