1 cup sugar
3/4 cup fresh lemon juice
3 large eggs
3 large egg yolks
1/4 cup (1/2 stick) chilled unsalted butter, cut into 1/2-inch cubes
6 large eggs, separated
14 tablespoons sugar
1 3/4 cups sifted cake flour (sifted, then measured)
1/4 teaspoon salt
1/2 cup sugar
1/2 cup boiling water
1/4 cup fresh lemon juice
Filling and frosting:
2 cups chilled heavy whipping cream
3/4 cup sugar
3 8-ounce containers chilled mascarpone cheese (Italian cream cheese available
at Italian markets and many supermarkets; if not available can be substituted
with sour cream)
Begin making this cake two days before you plan to serve it.
For the lemon curd:
Whisk the first 4 ingredients (sugar, lemon juice, eggs and egg yolks) in a
medium metal bowl. Set the bowl over a saucepan of simmering water (do not allow
the bottom of the bowl to touch the bottom of the saucepan). Whisk
constantly until thickened. An instant-read thermometer inserted into the
mixture should register 160 F, about 10 minutes. Remove the bowl from the water.
Add the butter; whisk until melted. Transfer 1 cup of the curd to a small bowl
for spreading onto the cake layers. Reserve the remaining of the curd for
filling. Press a plastic wrap directly onto the surface of both curds. Chill
overnight. (Can be made 3 days ahead. Keep chilled.)
For the cake:
Position a rack in the center of the oven and preheat to 375 F. Line the bottom
of two 9-inch-diameter cake
pans with 1 1/2-inch-high sides with parchment paper (do not grease pans or
parchment). Using an electric
mixer, beat the egg yolks and 7 tablespoons sugar in a large bowl until the
mixture is very thick and slowly dissolving ribbons form when the beaters are
lifted, about 4 minutes. Using clean dry beaters, beat the egg whites in another
large bowl until soft peaks form. Add the remaining 7 tablespoons sugar, 1
tablespoon at a time, beating until stiff and glossy. Fold half of the egg
whites into the yolk mixture, then sift half of the flour and 1/4 teaspoon salt
over and gently fold in until incorporated. Fold in the remaining egg whites,
then sift the remaining flour over and fold in just until combined, being
careful not to deflate the batter.
Divide the batter between the two pans; smooth tops. Bake until a tester
inserted into the center of the cakes comes out clean, about 15 minutes. Cool in
the pans on racks.
Run a knife around the edge of the pans to loosen the cakes. Invert the cakes
onto the work surface. Cut each cake horizontally in half (layers will be thin).
Peel off the parchment.
For the syrup:
Place the sugar in a small metal bowl. Add 1/2 cup boiling water; stir to
dissolve the sugar. Stir in the lemon juice.
For the filling and the frosting:
Beat the whipping cream and the sugar in large bowl until peaks form. Add the
mascarpone to the lemon curd in a medium bowl; whisk until blended. Fold the
whipped cream into the lemon-mascarpone mixture.
Place 1 cake layer, flat side up, on a platter. Brush with 1/4 of the syrup.
Using a spatula
spread 1/4 cup lemon curd over, then 1 cup lemon-mascarpone filling. Top with
the second cake layer; brush with 1/4 of the syrup and spread with 1/4 cup lemon
curd and 1 cup lemon-mascarpone filling. Repeat with the third cake layer,
syrup, lemon curd, and filling. Top with fourth cake layer. Brush with the
remaining syrup, then spread the remaining lemon curd over. Spoon 2 cups lemon-mascarpone
filling into a pastry bag fitted with 1/4-inch star tip (to be used for
rosettes). Using a spatula spread the remaining lemon-mascarpone filling as a
frosting over the sides of the cake. Pipe small rosettes of frosting over the
top of the cake, covering the top surface completely. Cover the cake with a cake
dome; refrigerate at least 6 hours and up to 1 day.