Martha Stewart's Yellow Cake

CAKE: Arrange two racks in the center of oven, and heat oven to 350
degrees. Line the bottoms of two 8- by 2-inch buttered cake pans with
buttered parchment paper. Dust the bottoms and sides of pans with flour,
and tap out any excess. Sift together the flour, baking powder, baking
soda, and salt; set aside. In the bowl of a standing mixer, cream butter at
medium speed until softened, 1 to 2 minutes. Gradually add sugar, and
continue 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 the 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. 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; set cakes top-side down on wire racks, and allow to cool completely,
about 1 hour. (Makes two 8-inch layers) LEMON FILLING: Sift sugar,
cornstarch and salt into a medium saucepan. Gradually blend in the cold
water and lemon juice. Place saucepan over medium-low and whisk until
smooth. Add the eggs and 2 tablespoons butter and blend thoroughly. Stir
constantly with a wooden spoon until thickened and add the boiling water.
Continue stirring until the mixture reaches the desired thickness, about 2
to 3 minutes. Remove from heat and stir in the lemon peel; rub surface
lightly with 1 tablespoon butter to prevent a skin from forming.
Refrigerate unused portion for up to 1 week. (Makes 2 cups) RICH CHOCOLATE
FROSTING: Place chocolate and cream in heavy saucepan. Cook over low heat,
stirring constantly with a rubber spatula, until combined and thickened, 20
to 25 minutes. Increase heat to medium-low, and cook, stirring, 3 minutes
more. Remove from heat; stir in corn syrup. Transfer to a large metal bowl;
refrigerate. Check every 15 to 20 minutes; stir until cool enough to
spread, about 2 hours. Spread on cooled cake. (Makes 6 cups) ASSEMBLY:
Remove the parchment paper from each cake; reserve the one with flattest
bottom surface to use for the top layer of the assembled cake. Place the
other cake, top-side down, on the serving platter as the first layer.
Spread a 1/2-inch thick layer lemon filling to within a 1/2-inch from the
edge. Place remaining cake, top-side down, on top of the first and press
down slightly. If the kitchen is warm and the lemon filling seems runny,
transfer the cake to the refrigerator to firm up the filling. Ice with a
rich chocolate frosting. Chill cake until frosting sets, about 10 minutes,
and serve.