Magnolia Bakery's Vanilla Birthday Cake and Frosting

These comments are from their cookbook: "At Magnolia we decided to make our cake not quite a traditional yellow cake or a traditional sponge cake, given the use of whole eggs in our recipe. We're sure you'll agree this recipe is moist, delicious and makes a beautiful layer cake or cupcakes for birthdays or any celebration. Frost with pink buttercream icing and lots of colored sprinkles as we do, and feel as though you're at your seventh birthday party all over again!"