In a mixing bowl, cream together the softened butter and granulated sugar until light and fluffy.

Beat in the egg, vanilla extract, lemon zest, and lemon juice until well combined.

In a separate bowl, whisk together the all-purpose flour, baking powder, and salt.

Gradually add the dry ingredients to the wet mixture, mixing until a soft dough forms.

Divide the dough into two portions and roll each into a log shape.

Wrap the logs in plastic wrap and refrigerate for at least 1 hour or until firm.

Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

Slice the chilled dough logs into 1/4-inch thick rounds and place them on the prepared baking sheet.

Bake for 10-12 minutes or until the edges turn golden.

Let the cookies cool on a cooling rack for a few minutes.

Dust the cookies with powdered sugar while they are still slightly warm.