It's time to celebrate with this buttermilk cake with a vanilla buttercream icing chock full of sprinkles.
Stop the mixer and scrape down the sides of the bowl. Beat in the eggs, one at a time, beating for 1 minute between each addition. Beat in vanilla extract.
Pour batter into prepared pans. Bake for 25 – 30 minutes or until cooked through and the top springs back lightly when touch. Test the cake by inserted a skewer into the center of the cake. The cake is done when just a few crumbs are left on the skewer.
In the bowl of an electric mixer fitted with the paddle attachment, beat the butter on medium speed until soft, about 1 minute. Add in 2 cups of the confectioners’ sugar. Then, add the salt and vanilla.