Preheat your oven to 350°F (175°C).
In a bowl, whisk together the gluten-free flour, baking powder, and salt.
In a separate mixing bowl, cream the softened butter and granulated sugar until light and fluffy.
Add the egg, lemon zest, and lemon juice to the butter-sugar mixture and mix well.
Gradually mix the dry ingredients into the wet mixture until just combined.
Chill the dough in the refrigerator for 30 minutes.
Scoop tablespoon-sized balls of dough and roll them in powdered sugar.
Place the dough balls on a parchment-lined baking sheet, spaced at least 2 inches apart.
Bake in the preheated oven for 10-12 minutes or until the edges are lightly golden.
Allow the cookies to cool on the baking sheet for a few minutes before transferring to a wire rack to cool completely.