Preparation

1. Set aside a 23 by 33 cm (9 by 13 inch) casserole dish or a footed glass bowl. In a mixing bowl, stir together the espresso and 45 ml (3 tablespoons) of the rum. Quickly dip half of the ladyfingers, one at a time, on one side only, and arrange in a single layer in the bottom of the dish. They should be moist, but do not soak them or the cake will collapse.

2. In a separate bowl, whisk together the egg yolks and sugar. Place over steam (over a saucepan with simmering water) and whisk over low heat for about 10 minutes, until the sugar has melted and the mixture is lighter in color and slightly thickened. Remove from heat and whisk for a few minutes off the heat to help it cool down, then set aside to cool while doing the next step.

3. In the bowl of an electric mixer, beat together the mascarpone and remaining 45 ml (3 tablespoons) rum. In a separate bowl, beat the cream until stiff peaks form. Use a spatula to gently fold half of the whipped cream into the mascarpone cream, then blend in remaining whipped cream just until incorporated.

4. If lining the edge of a bowl with ladyfingers, dip them, dust with cocoa, and arrange vertically in the bowl. Spread half of the cream over the first layer of ladyfingers. Dip and arrange another layer of ladyfingers. Add the remaining cream and spread it evenly. Refrigerate overnight. Dust with cocoa powder before serving*. Garnish with chopped chocolate.