Heat oven to 375 degrees. Arrange ladyfingers on a bking sheet and bake until toasted golden, 5 to 10 minutes. Arrange half the ladyfingers in a 2 or 2 1/2 inch deep oval or rectangular serving dish. Brush lightly with espresso. In a large mixing bowl, beat egg whites at high speed with electric mixer until they are stiff. Set aside. In a small mixing bowl, beat egg yolks and sugar at medium speed with electric mixer until thick and lemon colored. Add mascarpone and brandy. Stir gently. Gently fold egg whites into the mascarpone mixture. Spread half the mixture on the ladyfingers in the serving dish, then sprinkle with half the chocolate. Repeat layers of lady-fingers, mascarpone mixture and chocolate. Cover with foil. Refrigerate for at least an hour.