Tiramisu is either a precisely calibrated dessert or a bowl of mascarpone and ego, and the difference is always the sabayon. Jewel Johnson — co-owner of Poppa's Custard Company in Philadelphia and executive chef at Dirty French in New York — has been thinking about custard long enough to know which side of that line she lives on.
Johnson's sabayon runs six egg yolks to 75 grams of sugar, whipped over a double boiler at 140°F — hot enough to pasteurize without scrambling — until the ribbon holds its shape for ten seconds before dissolving. The mascarpone is folded in thirds, not whisked, which keeps the air that took four minutes to build from collapsing in thirty seconds of impatience. The ladyfingers are dipped in cold espresso for exactly two seconds per side — any longer and they become a sponge that collapses the structure.
Drive to Poppa's Custard in Philadelphia and order whatever she's made that day. It will be more carefully thought through than anything Bobby Flay assembled in a twenty-minute heat.