250 ml guinness
250 gram(s) unsalted butter
75 gram(s) cocoa powder
400 gram(s) caster sugar
142 ml sour cream
2 medium egg(s)
1 tablespoon(s) vanilla extract
275 gram(s) plain flour
2.5 teaspoon(s) bicarbonate of soda
For the topping
300 gram(s) cream cheese
150 gram(s) icing sugar
125 ml double cream (or whipping cream)
Preheat the oven to gas mark 4/180°C, and butter and line a 23cm springform tin.
Pour the Guinness into a large wide saucepan, add the butter - in spoons or slices - and heat until the butter's melted, at which time you should whisk in the cocoa and sugar. Beat the sour cream with the eggs and vanilla and then pour into the brown, buttery, beery pan and finally whisk in the flour and bicarb.
Pour the cake batter into the greased and lined tin and bake for 45 minutes to an hour. Leave to cool completely in the tin on a cooling rack, as it is quite a damp cake.
When the cake's cold, sit it on a flat platter or cake stand and get on with the icing. Lightly whip the cream cheese until smooth, sieve over the icing sugar and then beat them both together. Or do this in a processor, putting the unsieved icing sugar in first and blitz to remove lumps before adding the cheese.
Add the cream and beat again until it makes a spreadable consistency. Ice the top of the black cake so that it resembles the frothy top of the famous pint.