As nineteenth-century celebrity chef F. G. Zenker explained in his 1824 cookbook Der Zuckerbäcker Für Frauen Mittlerer Stände (Confectionary for Middle Class Ladies), lightness is everything. Viennese Carnival donuts must be so ethereal that they do not sink more than halfway into the hot lard; this is how they receive the characteristic pale ring around their middles. There used to be a time when you would find these only for Carniva