The vanilla buttercream we use at the bakery is technically not a buttercream but actually an old-fashioned confectioners' sugar and butter frosting. Be sure to beat the icing for the amount of time called for in the recipe to achieve the desired creamy texture.
1 cup (2 sticks) unsalted butter, softened
6 to 8 cups confectioners' sugar
1/2 cup milk
2 teaspoons vanilla extract
Place the butter in a large mixing bowl. Add 4 cups of the sugar and then the milk and vanilla. On the medium speed of an electric mixer, beat until smooth and creamy, about 3 to 5 minutes. Gradually add the remaining sugar, 1 cup at a time, beating well after each addition (about 2 minutes), until the icing is thick enough to be of good spreading consistency. You may not need to add all of the sugar. If desired, add a few drops of food coloring and mix thoroughly. (Use and store the icing at room temperature because icing will set if chilled.) Icing can be stored in an airtight container for up to 3 days.
Yield: enough for 2 dozen cupcakes or 1 (9-inch) layer cake