Lemon-Lattice White Chocolate Cake

PreparationFor lemon curd: Combine lemon juice and cornstarch in heavy medium saucepan, stirring until cornstarch dissolves. Whisk in remaining ingredients. Cook over medium heat until mixture is thick and smooth and just begins to boil, stirring constantly, about 7 minutes. Transfer to medium bowl. Place plastic wrap directly on surface of curd to prevent skin from forming. Refrigerate until chilled, about 6 hours. (Can be prepared days ahead.) For frosting: Combine 1/2 cup cream and chocolate in heavy small saucepan. Stir over low heat until chocolate melts and mixture is smooth. Transfer to large bowl. Whisk in remaining 1 3/4 cups cream and vanilla. Refrigerate until well chilled, about 6 hours. (Can be prepared up to 1 day ahead.) For cake: Position rack in center of oven and preheat to 350°F. Butter three 9-inch-diameter cake pans with 1 1/2-inch-high sides. Line bottoms with waxed paper. Butter paper. Dust pans with flour; tap out excess. Sift flour, baking powder and salt together into medium bowl. Repeat sifting. Stir chocolate and 1/2 cup cream in heavy medium saucepan over low heat until chocolate melts and mixture is smooth. Mix in remaining 1/2 cup cream, milk and vanilla. Using electric mixer, beat butter and 1 cup sugar in large bowl until fluffy. Beat in yolks. Stir dry ingredients into butter mixture alternately with white chocolate mixture, beginning and ending with dry ingredients. Using electric mix fitted with clean dry beaters, beat egg whites in medium bowl to soft peaks. Gradually beat in remaining 1 cup sugar. Continue beating until stiff but not dry. Fold whites into cake batter in 2 additions. Divide batter among prepared cake pans. Bake until tester inserted in center comes out clean and cakes are beginning to pull away from sides of pans, about 24 minutes. Cool cakes in pans on racks 10 minutes. Turn cakes out onto racks, peel off waxed paper and cool completely. (Can be prepared 4 hours ahead. Cover and let stand at room temperature. Using electric mixer, beat frosting in another large bowl until stiff peaks form. Place 1 cake layer on platter. Spread 2/3 cup lemon curd evenly atop cake layer. Spread 3/4 cup frosting atop curd. Top with second cake layer. Spread cake with 2/3 cup curd, then with 3/4 cup frosting. Top with third cake layer. Frost top and sides of entire cake evenly with 3 cups frosting. Place remaining lemon curd in pastry bag fitted with no. 2 star tip. Pipe circle of curd around top of cake, 1/2 inch from edge. Pipe evenly spaced diagonal lines inside circle, creating lattice pattern. (Reserve remaining curd for another use.) Spoon remaining frosting into clean pastry bag fitted with no. 2 star tip. Pipe ruffled border around top and bottom edges of cake. (Can be prepared up to 6 hours ahead. Refrigerate.) Let stand at room temperature 30 minutes before serving.

PreparationFor lemon curd: Combine lemon juice and cornstarch in heavy medium saucepan, stirring until cornstarch dissolves. Whisk in remaining ingredients. Cook over medium heat until mixture is thick and smooth and just begins to boil, stirring constantly, about 7 minutes. Transfer to medium bowl. Place plastic wrap directly on surface of curd to prevent skin from forming. Refrigerate until chilled, about 6 hours. (Can be prepared days ahead.) For frosting: Combine 1/2 cup cream and chocolate in heavy small saucepan. Stir over low heat until chocolate melts and mixture is smooth. Transfer to large bowl. Whisk in remaining 1 3/4 cups cream and vanilla. Refrigerate until well chilled, about 6 hours. (Can be prepared up to 1 day ahead.) For cake: Position rack in center of oven and preheat to 350°F. Butter three 9-inch-diameter cake pans with 1 1/2-inch-high sides. Line bottoms with waxed paper. Butter paper. Dust pans with flour; tap out excess. Sift flour, baking powder and salt together into medium bowl. Repeat sifting. Stir chocolate and 1/2 cup cream in heavy medium saucepan over low heat until chocolate melts and mixture is smooth. Mix in remaining 1/2 cup cream, milk and vanilla. Using electric mixer, beat butter and 1 cup sugar in large bowl until fluffy. Beat in yolks. Stir dry ingredients into butter mixture alternately with white chocolate mixture, beginning and ending with dry ingredients. Using electric mix fitted with clean dry beaters, beat egg whites in medium bowl to soft peaks. Gradually beat in remaining 1 cup sugar. Continue beating until stiff but not dry. Fold whites into cake batter in 2 additions. Divide batter among prepared cake pans. Bake until tester inserted in center comes out clean and cakes are beginning to pull away from sides of pans, about 24 minutes. Cool cakes in pans on racks 10 minutes. Turn cakes out onto racks, peel off waxed paper and cool completely. (Can be prepared 4 hours ahead. Cover and let stand at room temperature. Using electric mixer, beat frosting in another large bowl until stiff peaks form. Place 1 cake layer on platter. Spread 2/3 cup lemon curd evenly atop cake layer. Spread 3/4 cup frosting atop curd. Top with second cake layer. Spread cake with 2/3 cup curd, then with 3/4 cup frosting. Top with third cake layer. Frost top and sides of entire cake evenly with 3 cups frosting. Place remaining lemon curd in pastry bag fitted with no. 2 star tip. Pipe circle of curd around top of cake, 1/2 inch from edge. Pipe evenly spaced diagonal lines inside circle, creating lattice pattern. (Reserve remaining curd for another use.) Spoon remaining frosting into clean pastry bag fitted with no. 2 star tip. Pipe ruffled border around top and bottom edges of cake. (Can be prepared up to 6 hours ahead. Refrigerate.) Let stand at room temperature 30 minutes before serving.