Using an electric mixer, cream together the softened butter and cream cheese in a large bowl. Beat for 3 minutes on medium-high speed until fluffy and pale yellow in color.
To the bowl add vanilla, lemon extract and lemon zest, beating just until combined.
Lower the speed of the mixer and begin to add the powdered sugar alternately with the thawed pink lemonade concentrate. Stop and scrape the sides of the bowl periodically, so all of the ingredients will combine.
Add a few drops of red or pink food coloring until it reaches desired color.
After all of the ingredients have been added, increase the speed of the mixer and beat on high speed for 2-3 minutes or until fluffy and no lumps remain.
Store chilled in an airtight container for up to one week. Beat using a mixer prior to using.
Notes
6 cups to frost: 36 cupcakes, one 3 layer [8] inch layer cake, more than enough for a standard 13 x 9 sheet cake