Preheat oven to 350 degrees.
In a mixing bowl whisk together flour, baking powder and salt.
Using a stand or hand mixer, whip together butter, sugar and lemon zest until pale and fluffy.
Mix in egg then blend in egg yolk.
Add lemon juice, lemon extract, vanilla extract and mix until combined.
With mixer set on low speed (if using stand mixer) slowly add in dry ingredients and mix just until combined.
Pour powdered sugar into a small bowl.
Scoop dough out about 1½ tbsp at a time and shape into a ball, then drop in powdered sugar and roll to evenly coat.
Transfer to a parchment paper 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 in an airtight container.