Sift flour, baking powder, and salt together. Set aside
Using hand mixer, mix butter and sugar until fluffy.
Add lime juice, zest, vanilla, and egg and mix until well blended
Add flour mixture and mix until incorporated. Cover and set in refrigerator to chill for at least 1 hour.
When ready to bake, pre heat oven to 180C
Using small cookie scoop, scoop 1 tablespoon of dough and roll to form a ball
Coat with sanding sugar and place on parchment paper lined cookie sheet.
Flatten cookie with bottom of glass that you have dipped in sugar first.
Bake cookies 8-12 minutes (I went about 10 minutes).
Cool slightly before removing from cookie sheet.
Store in a cool, dry place
Makes 24 cookies