Reader Tom writes in from Vienna:
The Rehrücken is traditionally part of the Austrian confection of pastry, like Sacher Torte. Yet I have no evidence to prove it except it is really traditional. [Your recipe] is kind of strange because of the ginger, which is definetly not part of any Rehrücken-recipe here. Same goes for raspberry or apricot jam. Same for instant coffee. And we don’t “fill” the Rehrücken with any jam. We glaze the *whole* thing with (a rather sour tasting) red currant jam and then one more time with chocolate, and we insert the almonds always after glazing… otherwise the almonds will look dirty, and they have to be pearly white. Oh, by the way… we insert whole white almonds, not slivered ones.
Other than that, my version was 100% authentic.