Melt the chocolate and butter in a saucepan over low heat, while stirring continuously. Remove it from the heat and allow it to cool slightly.
In a large bowl, beat the eggs with the sugar until thick and pale in color.
Beat the melted chocolate mixture into the egg mixture until combined.
Beat in the coffee and milk.
Beat in the flour and baking powder until the batter is smooth and free of lumps.
Pour the batter into a 20 cm baking tin. Bake it in a 180 C (356 F) oven for 50 minutes.
Serve the cake dusted with icing sugar.
