Preheat oven to 350 degrees.
Grease light colored baking sheets w/ non-stick cooking spray, set aside.
In large bowl, cream butter & sugar together until light & fluffy. Whip in vanilla, egg, lemon zest, & juice. Scrape sides and mix again. Stir in all dry ingredients (except powdered sugar) slowly until just combined. Scrape sides of bowl & mix again briefly.
Pour powdered sugar into a large plate. Roll a heaping teaspoon of dough into a ball and roll in the powdered sugar. Place on baking sheet and repeat with remaining dough.
Bake for 7-9 minutes or until bottoms begin to barely brown and cookies have a matte (not melty or shiny). Remove from oven and cool cookies about 3 minutes before transferring to cooling rack.
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