Use a small 6" or 15 cm cake tin. And set the Oven to 185 C / 350 F
Put the coffee, sugar, butter, bi carbonate of soda and cocoa into a medium pot that will later fit the other ingredients comfortably. Stir over a low heat till JUST melted. Cool.
Add the beaten eggs and stir well then the sifted flour and baking powder and mix with a whisk till well combined.
Pour into the cake tin and bake for approx 50 minutes or until a skewer inserted in the centre comes out clean
To make the icing the easy way.
Put all the ingredients into a food processor and blitz till dark and well combined. Or put into a bowl and whisk together.