In a medium bowl, whisk together the flour and salt. Set aside.

In the bowl of a stand mixer fitted with the paddle attachment, beat the butter for 1 minute on medium speed. Add 1/2 cup of the granulated sugar and brown sugar and mix until light and fluffy, about 2 minutes. Scrape down the sides of the bowl with a spatula, as necessary. Add the egg yolk and vanilla extract and mix until well combined.

Add the dry ingredients and mix on low until just combined.

Roll the dough into balls, about 1 1/2 teaspoons per cookie. Place the remaining 1/2 cup sugar in a small bowl. Roll the balls in the sugar until well coated.

Place on a baking sheet that has been lined with parchment paper or a Silpat baking mat, you may need 2 sheets.

Use the rounded back of a teaspoon or your thumb to gently press an indentation in the center each cookie dough ball. Transfer the baking sheet to the freezer and chill for 30 minutes.

Preheat the oven to 350 degrees F.

Make sure the cookies are 2-inches apart on the baking sheets. Bake one pan at a time, for 10 to 12 minutes or until the edges are light golden brown.

Remove from the oven and let the cookies cool on the baking sheet. Enjoy!