Beat the butter and sugar in a deep bowl until the mixture is fluffy. Add eggs, then the flour together with the baking powder. Mix well and add the melted chocolate steam. Pour the mixture into a medium oiled tray. To avoid then the separation of the base, use 2 equal sized trays and spread the mixture evenly. If you do not have any, you the base to it with a knife around the edge and divide it by a thread. Bake for an hour and a half of 140 C. Chilled removing it from the tray (divide it in two). Frosting: Melt chocolate with cream. Spread the entire cake (and between the bases). You can decorate it with whatever you have using your imagination.