This frosting has at least three times the amount of lemon juice most recipes of the other recipes I’ve seen call for. It has a tart hit like a lemon curd or lemon meringue pie, along with the sweet, creamy smoothness of a luscious buttercream.
The frosting is shown here on a birthday cake for a lemon-loving teenager- hence the massive quantities of rainbow sprinkles!
1 stick/ 4 oz./125 g. salted butter, softened
6 Tbs. / 75 ml. freshly squeezed lemon juice
½ tsp. vanilla extract
3 cups / 350 g. confectioners’ sugar
Beat the butter with an electric mixer 2 minutes, or until very soft and creamy. Add 3 tablespoons of the lemon juice and the vanilla, and beat on low speed until combined. Add half of the confectioners’ sugar, and beat on low speed until smooth. Add the remaining lemon juice, then the remaining confectioners’ sugar, and beat on low speed till combined. Turn the speed up on the mixer, and beat 3 minutes, or until the frosting is light and fluffy, adding more confectioners’ sugar if necessary to have a smooth, spreadable consistency. Makes 2 ½ cups, or enough for 1 8-inch layer cake