For the chocolate cake, melt the butter and chocolate over a water bath. Stir again and again.
Mix eggs and sugar – do not beat! When the chocolate-butter mixture is no longer warm, mix with the egg-sugar mixture and then fold in the flour.
Pour into buttered ramekins and bake at about 180 °C for about 12 to 13 minutes. Remove the mixture from the mold with a knife before inverting.