Melt the chocolate with the coffee in a
heatproof bowl set over a pan of gently simmering water. Meanwhile,
cream together the butter or margarine and sugar until light and
fluffy. Gradually add the eggs, beating well after each addition. Stir
in the melted chocolate, then fold in the flour and baking powder.
Spoon the mixture into a greased and lined 900 g/2 lb loaf tin (pan)
and bake in a preheated oven at 190ºC/375ºF/g mark 5 for about 1 hour
until a skewer inserted in the centre comes out clean. If necessary,
cover the top with foil or greaseproof (waxed) paper for the last 10
minutes of cooking to prevent over-browning.