Instructions

Sponge Cakes

1. Preheat the oven to 375°F. line the bottoms of two 8-inch (20 cm) cake pans with parchment rounds. Do not grease the pans.
2. Whip the egg yolks and 7 tablespoons of the sugar at high speed until thick and very light in color, 4 to 5 minutes.
3. In another bowl, whip the egg whites on medium speed to soft peaks. With the mixer running, gradually add the remaining 7 tablespoons of sugar; continue beating until the egg whites hold firm peaks.
4. Fold one-third of the egg whites into the beaten yolks with the spatula, then use the fine-mesh strainer to sift half of the flour over the top and gently fold it in. Repeat. Fold in the last of the egg whites until no streaks of white remain.
5. Divide the batter evenly between the prepared pans. Bake for 18 minutes, until the tops are golden, firm to the touch, and a toothpick inserted into the centers comes out clean.
6. Let cool for a few minutes then run a knife around the outside edge of each cake to loosen it from the pan. Turn each cake out onto your hand (covered with an oven mitten) and then transfer it parchment side down onto a wire rack to cool completely.

Lemon Syrup

Heat the sugar and water in the small saucepan, stirring occasionally, until the sugar has completely dissolved. Remove from heat and add the lemon juice. Let cool.

Mascarpone Filling

1. Whip cream and sugar until soft peaks form.
2. In a separate bowl, mix mascarpone and lemon curd until blended.
3. Gently fold in the whipped cream until the mixture is homogenous and thick. If the mixture becomes overworked, it will look grainy or separated. If this happens, stir in several tablespoons of cream with the spatula and stir just until the mixture has smoothed out again.

Assembly

1. Using a serrated knife, slice each cake horizontally into two layers. Set aside one of the bottom layers to use last.
2. Remove the parchment from the other bottom layer and place cut side up on the serving plate. Brush the cake with ¼ of the lemon syrup. Spread 1/6 of the mascarpone filling on top. Place 3 level tablespoons of lemon curd on top of the filling and spread evenly to the edge.
3. Place a second cake layer on top, cut side up, and repeat with lemon syrup, mascarpone filling and lemon curd. Place third layer on top, cut side up, and repeat.
4. Top with the last cake layer, placing it bottom side up (cut side down). Remove the parchment paper; the surface will be crumb-free for frosting. Moisten it with the remaining lemon syrup. Spread the remaining mascarpone over the top and sides of the cake.