1. Preheat oven to 180C / 350F / gas mark 4
2. Butter and line a 9" cake tin with greasproof paper
3. Cream butter and sugar and gradually add beaten eggs.
4. Sift together the flour, baking powder and bicarbonate of soda.
5. Melt the chocolate gently in a bowl in the microwave and add the cocoa powder to the melted chocolate. Once this is blended slowly add the stout to the mixture a little at a time remember that guinness should never be rushed nor the cook using it !
6. Add the flour and the Guinness mixture alternately to the cake mixture, stirring between each addition until completely mixed. The consistency will be soft.
7. Spoon into a deep 9" cake tin and bake for 1 - 1.25 hours. Bake until a skewer inserted into the centre of the cake comes out clean. You may need to cover the cake with foil or greaseproof paper after about 1 hour to prevent the top from browning.
8. Remove from the oven and leave to stand for 10 minutes before turning out onto a wire rack to cool.