How to Make It
In a medium bowl, whip the heavy cream until it is firm and refrigerate. In a large bowl, beat the egg yolks with the 1/3 cup of sugar until light in color. In another bowl, using a whisk or an electric handheld mixer, beat the egg whites until they hold soft peaks. Add the remaining 1 tablespoon of sugar to the whites and beat until they're firm and glossy. Using a rubber spatula, fold the whipped cream into the beaten yolk-and-sugar mixture, then fold in the mascarpone and one-third of the beaten egg whites. Gently fold in the remaining egg whites.
Pour the espresso into a shallow bowl. Dip both sides of half of the ladyfingers in the espresso and use them to line the bottom of an 8-by-10- or 8-by-11-inch glass or ceramic baking dish. Spoon half of the mascarpone mixture over the ladyfingers and spread it in a smooth, even layer. Dip both sides of the remaining ladyfingers in the espresso and arrange them on top. Spread the remaining mascarpone mixture over the ladyfingers in a smooth, even layer. Cover and refrigerate the tiramisu overnight.
Just before serving, sift the cocoa powder over the top of the tiramisu. Cut the tiramisu into squares and serve.
Savoiardi ladyfingers can be found in Italian specialty food shops.