Yellow Cake with Chocolate Buttercream Frosting

Directions

Preheat oven to 350 degrees. Butter 2 9-inch round baking pans, line with parchment paper and butter parchment. Lightly dust pans with flour and shake out excess, set pans aside. Sift all-purpose flour and cake flour into a mixing bowl. Add baking powder, baking soda and salt and whisk 20 seconds, set aside. In the bowl of an electric stand mixer fitted with the paddle attachment whip together butter and granulated sugar until pale and fluffy . Blend in vegetable oil. Mix in eggs one at time then blend in egg yolks. Mix in vanilla. Add in 1/3 of the flour mixture then mix just until combined, then add in 1/2 of the buttermilk and blend until combined, repeat process once more then finish by mixing in remaining 1/3 of the flour mixture. Scrape down sides and bottom of bowl with a rubber spatula. Divide batter among prepared cake pans. Bake in preheated oven 25 - 29 minutes until toothpick inserted into center comes out clean. Cool in pans several minutes, run knife around edge to make sure they are loose, then invert onto wire racks to cool . Frost with chocolate buttercream once cool.