In a large bowl place softened butter and sugar, beat until creamy.
Add the egg and beat until combined. Add lemon zest, lemon juice, vanilla extract and beat until combined.
Sift in flour, baking powder and salt. Fold until combined and soft dough is formed (at this stage you also can add yellow gel food coloring). Cover and refrigerate for 1 hour.
Preheat oven to 350F (180C).
Take the dough out of the fridge and shape into small balls. Cover each ball with powdered sugar and arrange them on a baking tray, leaving 2-inches apart.
Bake for 10-12 minutes.
Allow the cookies to cool for 5 minutes before transferring to a cooling rack.