01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together the flour and salt until well blended.
03 - In a large bowl, beat the butter and granulated sugar together until light and fluffy, approximately 3 minutes.
04 - Add the egg yolk and vanilla extract to the butter mixture. Mix until fully incorporated.
05 - Gradually add the flour mixture to the wet ingredients, mixing just until the dough comes together. Do not overmix.
06 - Roll tablespoon-sized portions of dough into balls. Place them 2 inches apart on the prepared baking sheets.
07 - Gently press each dough ball with fork tines or the bottom of a glass to flatten slightly.
08 - Bake for 10-12 minutes, or until edges are just turning golden. Avoid overbaking for best texture.
09 - Let cookies rest on baking sheet for 5 minutes, then transfer to wire rack to cool completely. Dust with powdered sugar if desired.