The secret of this light frosting is to mix it with a mixer for the recommended time at high speed. This incorporates air to make it light. 1-1/2 cups frosting is enough to frost the top of one 9 inch cake.
1 Combine all ingredients in bowl. Beat at low speed to mix. Beat at high speed until smooth and fluffy, approximately 5-10 minutes. If too stiff, beat in a few drops of water.