Preheat oven to 375°F.
Line a baking sheet with parchment paper or use a silpat liner.
In a mixing bowl, stir together the dry ingredients; flour, baking powder, and salt. Set aside.
In the bowl of a stand mixer, beat together on high speed, 2 sticks of softened butter and ¾ cup powdered sugar until light and fluffy.
Add the egg and the lemon zest and beat to combine.
Reduce mixer speed to low and add flour mixture a ½ cup at a time until completely combined.
Using a cookie scooper, place a scoop of dough onto prepared cookie sheet about 2 inches apart.
Use your fingers to flatten each ball of dough into a ½ inch thick round disc shape.
Bake cookies for 8-10 minutes, or until the centers are set. Cookies will not brown but they will be done.
Remove pan from the oven and allow cookies to remain on the cookie sheet for 5 minutes.
After 5 minutes, use a spatula to transfer the cookies onto a wire rack to cool completely.