Best Lemon Cake

Heat oven to 350 deg. Arrange two racks in the center of oven. Line the bottoms of two 8 x 2 inch buttered cake pans with parchment paper. Dust the bottoms and sides of pan with flour, and tap out any excess. Sift together the flour, baking powder, baking soda, and salt; set aside. Cream butter on medium until softened, 1 to 2 minutes. Gradually add sugar, and beat on medium until lightened, 3 to 4 minutes, scraping down sides once or twice. Gradually add eggs, beating after each addition until batter is no longer slick, stopping once or twice to scrape down sides, about 5 minutes. Slowly add the sifted flour mixture, alternating with the buttermilk, a little of each at a time, at low speed, beginning and ending with the flour mixture. Beat in the vanilla and the lemon zest. Divide the batter evenly between the prepared pans. Bake 25 minutes, and rotate the pans in the oven if needed for even browning. Continue baking until a cake tester inserted into the center of each cake comes out clean, 10 to 20 minutes more. Transfer pans to wire racks to cool. Let cool 15 minutes. Remove cakes from pans. Leave the cakes on a wire rack, tops up, to cool completely, about 1 hour. (Makes two 8-inch round layers) To assemble, remove the parchment paper from the bottom of each cake. Slice each layer in half horizontally with a serrated knife. Reserve the prettiest dome top to use for the top of the cake. Place the other top, dome-side down, on the serving platter to make the first layer. Spread with one cup of the lemon curd to within a half inch from the edge. Place the second layer over the first, and spread with curd, covering with third layer, and spreading with another cup of lemon curd. One hour before serving, transfer the platter with cake to refrigerator to firm up lemon curd (if the kitchen is warm and the curd gets runny, refrigerate the layers as they are completed). Just before serving, place the reserved domed layer on top of cake. Spoon on the sweetened whipped cream. Sprinkle with mixed berries and a dusting of confectioners' sugar through a fine sieve. Pass the egg yolks through a strainer to remove any traces of white. Combine the yolks, lemon zest, lemon juice, and sugar in a heavy saucepan. Whisk the mixture to combine, then switch to a wooden spoon. Stir constantly over medium heat, making sure to stir all the sides and edges of the saucepan for even cooking. Cook until the mixture is thick enough to coat the back of a spoon, 20 to 25 minutes. Remove the saucepan from heat. Add the butter, one piece at a time, stirring with a wooden spoon to incorporate into a smooth mixture. Transfer to a medium bowl, cover with plastic wrap, and place in the refrigerator until firm and chilled, at least one hour. (Makes 3 1/3 cups) Whip the heavy cream in the bowl of an electric mixer on medium speed until soft peaks form, 2 to 4 minutes. Add the vanilla and confectioners' sugar, and continue to whip on medium speed until the cream returns to soft peaks, 2 to 3 minutes. (Makes 1 1/3 cups) Yield: 1 eight-inch cake.