This lime frosting recipe is a fun and colorful topping for your next batch of cupcakes.
Cut up butter and shortening and put them in a mixing bowl. Mix them on high speed until light and fluffy.
Add in confectioners' sugar and key lime zest, mix slowly until incorporated, them mix on high speed for at least 10 minutes or longer. (you can't over mix this, the longer the better)
Add key lime juice and a little bit of green food colouring, mix in