Classic Tiramisu

Instructions

1. 1

   Set up a double boiler by bringing 1 inch of water to a bare simmer in a saucepan. In a heatproof bowl, whisk the egg yolks and sugar until pale, then set over the simmering water and whisk constantly for 8 to 10 minutes until the mixture is thick, glossy, and registers 160°F to safely cook the eggs.

2. 2

   Remove the bowl from the heat and whisk in the mascarpone a few spoonfuls at a time until completely smooth with no lumps; let cool to room temperature.

3. 3

   In a separate chilled bowl, whip the heavy cream to stiff peaks, then gently fold it into the mascarpone mixture in three additions to keep the cream light and airy.

4. 4

   Stir the rum into the cooled espresso in a shallow dish. Working one at a time, dip each ladyfinger into the espresso for just 1 second per side so they absorb flavor without turning soggy, then arrange a tight single layer in the bottom of a 9-inch square dish.

5. 5

   Spread half of the mascarpone cream evenly over the ladyfingers, then repeat with a second dipped layer and the remaining cream, smoothing the top.

6. 6

   Cover and refrigerate for at least 6 hours, ideally overnight, so the layers set and meld. Just before serving, dust the surface generously with cocoa powder through a fine sieve and finish with shaved bittersweet chocolate.