Preheat the oven to 180 C / Gas 4. Line a 12 hole muffin tin with paper cases.
In a bowl combine the butter and sugars and using a hand mixer, beat till the mixture is light and soft. Mix in the soured cream and coffee and slowly add the eggs in, one at a time, until well incorporated.
In another bowl roughly mix together the flour, cocoa and baking powder. Then sift half the mixture in to the liquid mixture and fold it in. Repeat for a second time adding in all the flour mixture until well incorporated. Spoon into the prepared paper cases filling only to 2/3 full to allow for a good rise.
Bake in the preheated oven for 15 to 20 minutes or until risen and a skewer inserted into the centre comes out clean. Remove from the oven and allow to cool on a cooling rack before serving or decorating.
This would go well with buttercream frosting. I will post my butter icing recipe soon!