准备

对于海绵蛋糕

• Heat the oven to 350°F. Line a rimmed sheet pan or jelly roll pan measuring 14×11 inches or 15×10 inches (or quite close to those measurements) with kitchen parchment. Using a stand mixer with its whisk attachment or an electric mixer, beat the egg yolks, 1/3 cup of the sugar, and the hot espresso on high until thick and voluminous, at least 6 minutes. In another bowl and with clean beaters, whisk the egg whites on medium speed. When they reach the soft-peak stage, slowly add the remaining 1/3 cup sugar with the mixer running. Increase the speed to medium high and beat until the whites are glossy and smooth with peaks that hold their shape without drooping, another 1 or 2 minutes. Fold one-third of the whites into the yolk mixture to lighten them, and then gently fold in the rest of the whites. Sift the flour and salt over the top of the mixture and fold it in gently. Spread the batter evenly on the prepared sheet pan. Bake until the center of the cake springs back when lightly pressed and the cake doesn’t stick to your fingers, 12 to 14 minutes. Remove from the oven and cool for 5 minutes. Run a knife around the edge of the cake and invert it onto a cooling rack. Gently peel off the parchment and allow the cake to cool completely.

用于填充

• 放一锅水以小火煮，然后用冰填充一个大碗。在一个中等不锈钢碗中，将蛋黄，糖，咖啡利口酒和盐搅拌均匀。将碗放在碗上，但不接触，煮沸的水和搅拌，直到混合物变稠，搅打叶子丝带从中落下，当您沿着6至7分钟的底部刮擦搅拌时，您可以看到碗的底部。通过将碗放在冰浴上并偶尔搅拌混合物来冷却蛋黄混合物。同时，将马斯卡彭和奶油搅拌均匀，直到达到峰值。当蛋黄混合物凉爽时，将奶油混合物轻轻折叠直至混合。保持混合物冷却。

For assembly

• Divide the sponge cake into thirds (three rectangles about 4-1/2×11 or 5×10 inches). Lay one of the cake rectangles on the bottom of a rectangular pan (I use a Pyrex baking dish). Brush its top liberally with one-third of the hot espresso. Spread just under half of the mascarpone filling over the cake. Grate about one-third of the unsweetened chocolate on top of the mascarpone. Repeat with another layer of cake, espresso, mascarpone filling, and chocolate. Top with the last layer of cake, brush on the last of the coffee, spread on a very thin layer of mascarpone, and grate the rest of the chocolate on top. Refrigerate for several hours or overnight before serving. Slice and serve.