Beat the butter, sugar and eggs until frothy. Mix the flour, baking powder, cocoa and starch, sift. Alternately add flour and milk to the dough.
First distribute some dough in paper cases, then place an After Eight on each one. Put some more batter on top, then another After Eight tablet. Finally, distribute the remaining dough.
Bake the muffins at 200 ° (preheated) for about 20 minutes!