Magnolia Bakery’s Buttercream Vanilla Icing

Place the butter in a large mixing bowl. Add 4 cups of the sugar and then the milk and vanilla extract. Beat until smooth and creamy. Gradually add the remaining sugar, 1 cup at a time, until the icing is thick enough to spread. Add a few drops of food coloring if desired. Frost cupcakes. Serve at room temperature. Leftover icing freezes well for up to two months.