Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a bowl, whisk together flour, baking powder, and salt.
In a separate bowl, cream the softened butter and granulated sugar until light and fluffy.
Add the egg, lemon zest, lemon juice, and vanilla extract to the butter mixture, and mix well.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Chill the dough in the refrigerator for about 30 minutes.
Scoop tablespoon-sized balls of dough and roll them in powdered sugar.
Place the sugar-coated dough balls on the prepared baking sheet.
Bake in the oven for 10-12 minutes or until the edges are set and the tops are slightly cracked.
Let the cookies cool on the baking sheet for a few minutes before transferring them to a wire rack.