- Cut the butter into chucks and place into a large mixing bowl. Add 4 cups of the 10xx sugar; then add the milk and vanilla straight away.
- On medium speed with 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 each), until the icing is thick and has a spreading consistency. You may not need to add all of the 10xx sugar. If desired, add a few drops of food coloring and mix thoroughly.
For a smooth and creamy buttercream frosting, all ingredients should be at the same temperature. If your liquid was not at room temperature the mixture cannot homogenize and will take on a curdled appearance (become soupy looking). This is a sign that the mixture is still too cold. Rapidly stirring and gentle warming will emulsify the buttercream to a smooth and creamy consistency. Continue to mix while using a hair dryer on the outside of mixing bowl until the perfect consistency is reached. For additional tips on how to make the perfect buttercream, watch our How to Fix a Broken Buttercream video.