Whip eggs with sugar until creamy. Mix the flour and baking powder and stir into the dough alternately with the butter. Then stir in milk and egg liqueur alternately with nuts and chocolate. Pour the dough into a springform pan, bake at 180 ° C for about 40 minutes.
Remove the cake from the mold and let it cool on a wire rack.
For the topping, chop the chocolate into small pieces with the oil in a double boiler
Stir gently over low heat and decorate the cake with the icing.