Butter 6 custard cups. Melt chocolate. In a double boiler, add butter and sugar and stir until mixed well. Transfer to a mixing bowl. Add eggs, flour, cocoa and baking powder. Beat until mixture thickens to mousse consistency (about 8 minutes). Divide into dishes and freeze at least 3 hours. May freeze up to 3 days before serving.
To serve: preheat oven to 375 deg. Bake until edges are set, center is still moist and surface is shiny (15-18 minutes). Do not overbake. Cool 10 minutes. Invert on a plate and serve with whipped cream. Yummy!