Preheat oven to 350° and either line cupcake tins with liners or grease and flour pans of your choice.
Sift together flour, baking powder, and salt. Set aside. In a separate bowl or in a stand mixer cream butter and sugar approximately 2-3 minutes. Add eggs, egg yokes and vanilla; beat well. Add flour mixture to creamed mixture alternately with milk. Beginning and ending with flour. Mix well and then pour into prepared pans.
Bake cupcakes approximately 15 minutes and cake approximately 40 minutes until a bamboo skewer inserted into the center comes out with only a few clinging crumbs. Let cool 5-10 minutes in pans and then tip out onto rack to cool completely before icing.
Ultimate Chocolate Frosting
Sift cocoa powder and confectioners’ sugar together in a medium bowl. Cream butter until fluffy. This will only take a minute if your butter is the proper temperature. Add vanilla, milk and sugar mixture to butter. Mix with the paddle attachment or a wooden spoon until smooth and butter is completely incorporated. Taste test. Just kidding!
Icing your cupcakes: Fit the desired tip onto your piping bag or cut a small hole in a plastic baggie and press tip snugly inside bag. Fill bag 75% with icing and squeeze icing down through the tip. Twist the top of the bag and squeeze the desired amount and shape of icing onto your cupcakes.
Frosting your layer cake: Place a dab of icing on serving platter and press bottom cake layer securely onto icing blob. Arrange parchment or wax paper around the edge of the cake to minimize mess on your platter.
Smear a thin layer of icing onto the top of the bottom layer. If it is too thick then your top layer(s) will slide around. Ugly. We don’t want that. Arrange your top layer on the bottom layer. Place a large dollop of icing on the top with a large, flat icing spatula and spread it around the top and sides of the cake. Don’t worry about precision here, you will add more and make it presentable later. Take your offset spatula and scoop a generous amount of icing. Gently sweep icing around the sides, removing any excess as you go. It helps if you are able to keep your spatula steady and move the cake platter. Take some more icing and smooth out the top with a gentle sweeping motion until you have achieved the desired effect. Lastly, smooth out the transition between the top and the sides.
Yellow Cake & Chocolate Frosting
Carefully remove the parchment paper and touch up the bottom edge. Admire your beautifully frosted cake!
Notes
Adapted from AllRecipes.com and Martha Stewart.Could also make two 9-inch round cakes, or one 9 x 13 inch pan.