FRANKFURT, Germany − Three ladies at table 3 lean forward to evaluate the bienenstich. The first declares the cake intolerable. “For these almonds, you need a magnifying glass,” the second sighs. The third rearranges her bronze-colored silk scarf and launches into a discourse on the proper proportions of cake and caramel: “Just a smattering of honey, no more!” The sound of a Csardas wafts through the room from...