01 -
Preheat the oven to 350°F. Line two baking sheets with parchment paper. Set aside.
02 -
Add the granulated sugar and lemon zest to a medium bowl. Use your hands to massage the zest into the sugar for about 30 seconds. This helps to release the oils from the zest into the sugar. Add the melted butter, lemon extract and vanilla extract. Whisk to combine well.
03 -
Add the egg, followed by the egg yolk, mixing to combine between each addition. Add the lemon juice and whisk to incorporate.
04 -
In a separate bowl, sift together the flour, baking powder, cornstarch and salt. Add the dry ingredients to the wet ingredients in two additions. Fold the dough together using a spatula, being careful not to over mix. Stop when a few streaks of flour remain.
05 -
Place the remaining granulated sugar and powdered sugar in separate bowls. Portion out the dough into 1 to 1.2 ounce balls and roll each ball first in the granulated sugar followed by the powdered sugar. Be sure to coat all sides generously.
06 -
Place the cookie dough balls on the prepared cookie sheet, spacing them about 2 inches apart. Bake for 9 to 11 minutes or until the cookies are puffy and set in the center. Do not over bake or the cookies will be dry.
07 -
Remove the cookies from the oven and allow to cool on the baking sheet for 10 minutes before carefully transferring to a wire rack to cool completely.