On a sheet of wax paper, stir together flour, baking powder and salt. From lemons,
grate 1 tablespoon of zest and squeeze 2 tablespoons juice.
In large bowl, with mixer at medium speed, beat butter, 1/2 cup granulated sugar
and confectioners' sugar until creamy. Beat in vanilla extract, lemon zest and
juice until blended. Reduce speed to low and beat in flour mixture just until combined.
Divide dough in half. Shape each half into 6-inch long log.
Wrap each log in wax
paper and refrigerate dough overnight.
Heat oven to 350 degrees F.
Keeping remaining log refrigerated, cut 1 log into scant 1/4-inch thick slices.
Place slices, 1 1/2 inches apart, on ungreased large cookie sheet. Sprinkle lightly
with some of remaining 2 tablespoons granulated sugar.
Bake 12 minutes or until
lightly browned at edges.
Cool on cookie sheet on wire rack 2 minutes.
spatula, transfer to wire rack to cool completely.