For the chocolate and ale cake, grease and flour a 25cm/10in loaf tin. Preheat the oven to 180C/350F/Gas 4.
Slowly mix the dark ale into the cocoa powder to form a paste.
In a separate bowl, beat the butter and soft dark brown sugar together until smooth and creamy, then add the eggs one at a time beating between each addition.
Stir in the cocoa and ale mixture. Sift in the flour, baking powder and bicarbonate of soda in batches, stirring between each addition.
Pour the cake batter into the prepared tin and bake for 30-35 minutes, or until springy to the touch. Cool on a wire rack.
Melt the chocolate in a heatproof bowl suspended over a pan of simmering water.
Beat the icing sugar and butter together to form a soft paste. Add four tablespoons of dark ale and then fold in the melted chocolate.
For the muscovado and malt cream, whip all the ingredients together in a large bowl until thick and smooth.
When the cake has cooled completely, cut it into slices.
Serve with the beer and chocolate icing spread over the cake and a dollop of muscovado and malt cream on the side.