Using fresh lemon zest and juice make the best lemon cupcakes so do not skip this necessary step in this cupcake recipe. I use a lemon zester to zest a lemon. However, if you do not have a zester, you can zest a lemon with a vegetable peeler or a cheese grater. When zesting a lemon, you want the yellow part of the skin and you do not want to zest into the white part of the skin. So watch closely when using any of these methods to zest a lemon.