Lemon Mascarpone Layer Cake

Instructions

1. Preheat the oven to 375º. Line two 9″ cake pans with parchment paper, but do not grease.
2. Whip the egg yolks with half of the sugar (7 tablespoons) in the bowl of a large stand mixer on high speed for 5 minutes, till very thick and light in color. Transfer the yolks to a separate bowl and wash the mixing bowl and whisk very well (any grease will prevent the whites from whipping properly).
3. Whip the egg whites till soft peaks form. Gradually add the remaining 7 tablespoons sugar a on high speed, until the egg whites hold firm peaks.
4. Fold one-third of the egg whites into the yolks with a spatula, then sift half of the cake flour on top and gently fold it in. Fold a second third of the egg whites into the yolks, sift the remaining cake flour on top, then fold that in. Finally, add the last of the egg whites, and when they’re almost incorporated, add the lemon zest and fold until everything is mixed together.
5. Divide the batter between the two pans and bake for 18-22 minutes, until the tops are golden, firm, and a toothpick inserted in the center comes out clean. Transfer the cakes to a rack to cool completely.
6. To make the lemon syrup, heat the sugar and water in a small saucepan over medium-high heat, stirring occasionally, until the sugar dissolves and the liquid is clear. Remove from the heat and stir in the lemon juice. Cool completely.
7. To make the lemon curd, place the eggs, yolks, and sugar in the top of a double boiler and whisk until blended. Add the lemon juice and mix well. Cook, whisking constantly, until the curd reaches 180º on a candy thermometer (do not let the curd boil).
8. Strain the curd through a metal strainer into a bowl. Add the cold butter pieces to the curd, and whisk gently until the butter is melted. Press some plastic wrap onto the surface of the lemon curd and chill 3-4 hours or overnight.
9. To make the mascarpone filling, place the cream and sugar in the large bowl of a stand mixer and whisk just until they form firm peaks.
10. In a large bowl, combine the mascarpone and 1-1/2 cups of lemon curd, and stir until they’re well-mixed. Gently fold the whipped cream into the mascarpone mixture but don't overmix.
11. To assemble the cake, use a sharp serrated knife to cut each of the cakes in half, making 4 thin cakes. Place one round on a serving plate, brush it with a quarter of the lemon syrup.
12. Spoon about ⅓ cup of the mascarpone filling on top of the cake round, and use a spatula to spread it evenly around. Top the mascarpone with about ⅓ cup of lemon curd, and spread it in a thin layer.
13. Place another cake round on top of the first, and brush with lemon syrup. Repeat the layer of cake rounds, lemon syrup, mascarpone, and lemon curd until you have added the final cake round to the top of the cake. Brush the top with the remaining lemon syrup.
14. Spread the remaining mascarpone mixture along the top and sides of the cake. You may want to reserve some to pipe decorations on top of the cake.