This is a Cinderella dessert story. From simple leftovers—some coffee, leftover cake or cookies, an enrichment of cream or mascarpone—a prince of a dessert is born.
- 1 pound bittersweet chocolate, chopped
- 2 cups heavy cream
- 2 cups mascarpone (1 pound), at room temperature
- 1 cup confectioners’ sugar
- 2 cups freshly brewed espresso
- ½ cup granulated sugar
- ½ cup coffee liqueur
- 48 ladyfingers (preferably imported Italian savoiardi)
Melt the chocolate in a double boiler over simmering water, and keep it warm in the double boiler. Meanwhile, whisk the cream in an electric mixer fitted with the whisk attachment until it just holds soft peaks. (Don’t overwhip—you will be whisking it again with the mascarpone, and you don’t want to make butter!)
Whisk the mascarpone in a separate bowl with the mixer at medium speed until smooth. Sift in the confectioners’ sugar, and whisk until it is smooth. Whisk the whipped cream into the mascarpone until they are just combined. Refrigerate if not using it right away.
Combine the espresso and granulated sugar in a medium saucepan set over low heat. Cook until the sugar has dissolved, then stir in the coffee liqueur. Remove it from the heat, and stir in about two-thirds of the melted chocolate. Pour the chocolate-espresso mixture into a large shallow pan, big enough to soak half the savoiardi at one time. Add half of the savoiardi to the liquid, and soak, turning to coat all sides until they are almost soaked through, about 1 minute.
Arrange the savoiardi in two rows in the bottom of a 9-by-13-inch (3-quart) Pyrex or ceramic dish to make a tight bottom layer, breaking as necessary to patch empty spaces. Drizzle with a third of the remaining warm melted chocolate. Spread half of the mascarpone in an even layer over the top of the cookies.
Soak the remaining twenty-four savoiardi in the remaining soaking liquid. Arrange these soaked savoiardi on top of the mascarpone, just as you did the first layer, and drizzle with another third of the warm melted chocolate.
Spread the remaining mascarpone in an even layer over the top. Pour the remaining melted chocolate on top. Use a toothpick or paring knife to make lines at 2-inch intervals connecting the long sides of the pan. Now make perpendicular lines through the chocolate, also at 2-inch intervals, to create a crosshatch pattern. Chill the tiramisù at least 4 hours, or up to overnight, before cutting into squares to serve.