Mix egg and water until it becomes foamy.
Add the remaining ingredients and mix.
Put the dough into a form.
Bake for 20 minutes at 200 degrees Celsius.
Mix icing and cocoa powder.
Spread icing on the buisquit.
Put the cake into the fridge.
Warning: My first try was too thin, the cream did not become hard enough. Some more experimenting is needed.
Mix butter and sugar.
Add the coffee and cocoa powder.
Slowly add the pudding.