½ cup plus 2 tablespoons sugar
¼ cup plus 2 tablespoons brandy
2 tablespoons instant espresso powder
1 ½ cups boiling water
4 large egg yolks
Pinch of table salt
1 pound mascarpone cheese, softened
1 teaspoon vanilla paste (or 1 tablespoon pure vanilla extract)
½ teaspoon finely grated orange zest (optional)
1 ½ cups heavy cream
36 large Savoiardi cookies (ladyfingers), from 2 (7-ounce) packages
4 ounces bittersweet chocolate, very finely chopped
2 tablespoons unsweetened cocoa
1. In a medium heat-proof bowl, combine 2 tablespoons of the sugar, 2 tablespoons of the brandy, the espresso powder, and the boiling water, stirring to dissolve the sugar. Let cool.
2. In a medium bowl, combine the egg yolks, salt, the remaining ¼ cup of brandy, and the remaining ½ cup of sugar and whisk until smooth. Set the bowl over a pot filled with 1 inch of just-simmering water. Cook, whisking constantly, until the sugar is dissolved and the mixture is thick, pale, and doubled in volume, about 8 minutes. Remove the bowl from the pot and gently whisk in the mascarpone, vanilla paste, and orange zest, if using.
3. In a separate bowl, beat the heavy cream until soft peaks form. Scrape the whipped cream into the mascarpone mixture and, using a rubber spatula, gently fold together.
4. Working with 1 ladyfinger at a time, dip the whole cookie very briefly into the espresso mixture and arrange it in an 8 x 11-inch (2-quart) glass or ceramic baking dish. To avoid sogginess, be careful not to oversaturate the ladyfingers. Repeat, using half of the ladyfingers to cover the bottom of the baking dish in neat rows. Spoon half of the mascarpone mixture over the ladyfingers and sprinkle with the chopped chocolate. Repeat with the remaining ladyfingers, espresso mixture (you’ll have some left over; don’t be tempted to pour it over the ladyfingers), and mascarpone mixture, spreading it to the edges of the dish. Lightly dust the surface with cocoa. Cover and refrigerate until firm, at least 6 hours, preferably overnight, before serving.