Lemon curd
7 large eggs
4 large egg yolks
1 cup fresh lemon juice
1 cup (2 sticks) unsalted butter, diced
3/4 cup sugar
2 1/2 tablespoons (packed) finely grated lemon peel

For lemon curd:
Whisk eggs and yolks in large bowl. Combine lemon juice, butter, and sugar in 
medium metal bowl. Set over saucepan of simmering water; stir until sugar dissolves. 
Gradually whisk hot lemon mixture into egg mixture. Return mixture to bowl set over 
water; whisk constantly until mixture thickens and instant-read thermometer registers 
180*F, about 5 minutes. Pour curd through fine strainer set over bowl; stir in lemon peel.
Place plastic wrap directly on surface of curd. Refrigerate until cold, at least 8 hours or 
overnight. (Can be made 2 days ahead. Keep refrigerated.)

For cake:
Position rack in center of oven and preheat to 325*F. Lightly butter two 9-inch-diameter 
cake pans with 2-inch-high sides. Line bottom of pans with parchment rounds. Sift first 
five ingredients into large bowl of stand mixer fitted with whisk attachment. Add butter, 
milk, and lemon peel and beat on medium-high speed until thick batter forms, about 2 
minutes. Add 4 egg whites; beat until smooth. Add remaining 4 egg whites; beat until 
well blended and smooth. Divide batter between prepared pans (about generous 4 1/2 
cups for each); smooth tops with offset spatula.

Bake cakes until golden and tester inserted into centers come out clean, about 45 
minutes. Cool in pans on rack 10 minutes. Turn cakes out onto racks; remove 
parchment and cool completely. (Can be prepared 1 day ahead. Wrap in foil and store 
at room temperature.)

Cut domed tops from both cakes, making each cake 1 1/4 to 1 1/3 inches high. Using 
long serrated knife, cut each cake horizontally in half. Place 3 cake layers on separate 
cardboard rounds or plates (reserve fourth cake layer for another use). Spread 1/3 cup 
preserves over top of each of 3 cake layers.

Transfer 1 cup curd to large bowl; reserve for mousse. Divide remaining curd among 
layers (generous 3/4 cup for each); spread evenly over preserves to edge of layers. 
Refrigerate layers separately while preparing mousse (do not stack cake layers).

For mousse:
Pour 1/4 cup water into small saucepan; sprinkle gelatin over. Let stand until gelatin 
softens, about 15 minutes. Place saucepan over low heat, stirring until gelatin 
dissolves, about 2 minutes (mixture will be lukewarm). Stir gelatin into reserved 1 cup 
lemon curd.

Using electric mixer, beat egg whites and 3 tablespoons sugar in large bowl until stiff 
but not dry. Fold egg whites into curd mixture in 2 additions; set aside until mousse 
begins to set slightly, about 10 minutes. Spoon 1/3 of lemon mousse (scant 1 cup) 
atop each layer, then spread gently to edges using offset spatula. Chill layers until 
mousse firms up slightly, about 30 minutes.

Place 1 cake layer on platter. Gently top with second, then third, being careful not to 
press down firmly. Refrigerate at least 2 hours. (Can be prepared 1 day ahead. Cover 
with cake dome and keep refrigerated.)
Garnish top edge of cake with white chocolate curls. Sprinkle pistachios and 
crystallized ginger in center of cake.

Test-kitchen tip:
For white chocolate curls, use a thick block of high-quality white chocolate. Microwave at 5-second intervals to soften slightly. Place the block of chocolate on a clean kitchen towel on a work surface. Using a vegetable peeler, peel off the chocolate in curls. Makes 10 to 12 servings.

Source: Bon Appétit