I make this frosting to go with the Pink Lemonade Cake I also submitted. It is SO good. If you would like, you can also add a drop of red food coloring to add a pink hue to the frosting as well.
In a large bowl beat butter, lemonade concentrate and zest at medium speed with a mixer until combined. Gradually add powdered sugar beating until smooth. If you would like, add a drop of red food coloring to make the frosting pink as well.