Step 1

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

Step 2

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.

Step 3

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

Step 4

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.

Step 5

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

Step 6

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.

Step 7

Preheat the oven to 350 degrees F.

Step 8

Fill a small zipper-lock bag with the jam. Use scissors to snip a small corner off the bag. Carefully fill each indentation with about a 1/2 teaspoon of jam. Don't over fill or the jam will ooze out in the oven. Less is best!

Step 9

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.

Step 10

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