Preheat oven to 350 degrees. In a mixing bowl whisk together flour, baking powder and salt.
In the bowl of an electric stand mixer fitted with the paddle attachment, whip together butter, sugar and lemon zest until pale and fluffy (occasionally scrape down bowl throughout entire mixing process if not using a paddle attachment that constantly scrapes bowl).
Mix in egg then blend in egg yolk. Add lemon juice, lemon extract, vanilla extract and optional yellow food coloring and mix until combined. With mixer set on low speed, slowly add in dry ingredients and mix just until combined.
Pour powdered sugar into a small bowl. Scoop dough out about 1 1/2 Tbsp at a time (25g each) and shape into a ball, then drop in powdered sugar and roll to evenly coat.
Transfer to a parchment paper or Silpat lined baking sheet, repeat with remaining dough and space cookies 2-inches apart on baking sheet. Bake in preheated oven 10 - 13 minutes.
Cool on baking sheet several minutes then transfer to a wire rack to cool.
Store these cookies in an airtight container at room temperature. Recipe Source: Cooking Classy