Preheat your oven to 350 degrees F and line a muffin tin with cupcake liners. Set aside.
In a small bowl, sift together flour, baking powder and salt.
Using an electric mixer, beat together butter, sugar and eggs. Add milk and lemon rind + juice.
In thirds, add dry ingredients into your wet ingredients.
Once batter is formed, add yellow gel food coloring and mix until completely tinted.
Fill your lined muffin tin with your cupcake batter (each about 2/3 full) and bake for 15 minutes (or, until a toothpick comes out clean when inserted in the center of a cupcake).
Allow the cupcakes to cool on a wire rack before decorating.
To make the buttercream, beat together butter, confectioners’ sugar and milk until smooth. Add yellow gel food coloring and beat until completely tinted.
Scoop the buttercream into a piping bag with Wilton icing tip #1M attached. Frost each cupcake.