For the cake:
200g (7oz) unsalted, softened butter
250g (9oz) plain flour
40g (11/2 oz) cocoa powder
11/2 tsp baking powder
225g (8oz) caster sugar
2 large eggs, beaten
250ml sour cream
1tbsp white wine vinegar
1tsp bicarbonate of soda
1/4 tsp red food colouring paste
For the icing:
400g (14oz) cream cheese
125g (4oz) unsalted, softened butter
125g icing sugar
Red sugar sprinkles to decorate
Preheat oven to 180C or Gas mark 4
Sift flour, cocoa powder and baking powder into a bowl. In a separate bowl beat the butter and sugar until pale and fluffy and beat in the eggs.
Alternately beat in the dry mixture and the sour cream into the butter mixture. Then beat in the vinegar, soda and colouring. The vinegar and soda fizz up to create bubbles in the mixture, it's this that gives the cake it's velvety texture.
Spoon the mixture into two cake tins with spring form bottoms or two lined tins and put on the middle shelf of the oven. Bake for 1hr - 1hr and 10mins.
Once out of the oven and tins leave to on a rack until completely cool.
To make the icing beat butter and add the icing sugar a bit at a time until you have butter icing, then beat in the cream cheese. Other recipes tell you to beat the butter and cream cheese together first but when I do this I get lumps of butter in my icing.
Make a sandwich with the cakes with the icing in the middle and on the top. Sprinkle with the red sugar.