Deluxe Chocolate Split Layer Cake with Chocolate Buttercream Frosting

Instructions

1. Prepare Cake: Preheat oven to 325°F. Grease two nine-inch round cake pans with some softened butter. Line bottom of pans with parchment paper; grease parchment with butter. Dust lined pans with flour. Onto sheet of waxed paper, sift flour, cocoa, baking soda, baking powder and salt. In two cup liquid measuring cup, combine buttermilk and vanilla.
2. In large bowl, with mixer on low speed, beat granulated sugar and butter until blended. Increase speed to high and beat four minutes or until creamy, occasionally scraping bowl with rubber spatula. Reduce speed to low; add eggs, one at a time, beating well after each addition and occasionally scraping bowl.
3. Beat in flour mixture alternately with buttermilk mixture just until blended, beginning and ending with flour mixture, scraping bowl occasionally. Pour batter evenly into prepared pans. Bake 25-30 minutes or until wooden pick inserted in center comes out with a few moist crumbs attached. Cool in pans on wire rack ten minutes. Run plastic knife around edges of pans to loosen cakes. Invert cakes onto racks. Remove parchment. Cool cakes completely, two hours.
4. Meanwhile, prepare Chocolate Buttercream Frosting: In microwave-safe medium bowl, heat chocolate in microwave oven on high one minute; stir. Heat one minute longer. Let stand a few minutes, then stir until smooth. Let stand fifteen minutes to cool slightly. With mixer on medium speed, beat butter three minutes or until creamy. Reduce speed to low. Add milk and vanilla and beat until blended. Increase speed to medium and beat one minute, occasionally scraping bowl with rubber spatula. Add cooled melted chocolate and beat two minutes. Reduce speed to low; gradually beat in powdered sugar. Increase speed to medium and beat two minutes, occasionally scraping bowl. Makes about seven cups of frosting.
5. With long, serrated knife parallel to work surface, split each cake layer horizontally in half to make four layers. Place one cake layer, cut side down, on cake plate. With narrow, metal spatula, spread 1 and 1/4 cups frosting over layer. Repeat with second and third layers, spreading 1 and 1/4 cups frosting between each layer. Top with fourth cake layer; spread remaining frosting on top and sides of cake. If not serving cake right away, cover loosely with plastic wrap and refrigerate up to one day ahead.