Work the margarine, sugar, flour, eggs and baking powder into a dough. Possibly add a little more milk. Spread the dough on a baking sheet lined with baking paper.
Make a kneading dough from sugar, butter, flour and cocoa, pluck it into crumble and place on the dough. Then bake the cake at about 175 degrees for 30-40 minutes. Pour the whipped cream over the cake while it is still warm.