In a mixing bowl, cream together butter and granulated sugar until light and fluffy.
Beat in the egg, vanilla extract, lemon zest, and lemon juice.
In another bowl, whisk together salt, baking powder, baking soda, and flour. Gradually add to the wet ingredients, mixing until just combined.
Roll dough into 1-inch balls and coat with powdered sugar. Place on a baking sheet about 2 inches apart.
Bake for 10 minutes, or until edges are lightly browned. Let cool on the baking sheet for a few minutes before transferring to a wire rack to cool completely.