This recipe for a traditional Blackforest Cake is taken from a German cookbook, Backen Schritt fur Schritt: Das Grundbackbuch für Sicheres Gelingen (1995). It makes a small and understated, but very satisfying, chocolate cake with a whipped cream frosting. I have left in the metric measure of dry ingredients because German bakers measure with weight rather than volume, which is more precise. You'll need a kitchen scale. This is a delicate operation, probably not for beginners, but it's well worth it.