Ingredients:

• 2 ⅓  cups of all-purpose flour
• 1 cup of unsalted butter
• ⅔ cups of white granulated sugar, plus ¼ cup for rolling 
• ¼ teaspoon of salt
• 2 large egg yolks
• 1 teaspoon of vanilla extract
• ½ cup of your favorite flavor of jam

Directions:

1. Preheat the oven to 350 degrees, and line two baking sheets with parchment paper.
2. In a large mixing bowl, cream together the butter and sugar with a hand-held mixer or stand mixer until well combined (around one to two minutes). Add vanilla extract, salt, and egg yolks and mix until just combined. Add the flour and mix. The dough may be crumbly at first, but will come together (should form a solid ball) as you continue to mix it together. 
3. Using a teaspoon, or your hands shape the dough into balls. Roll these balls in granulated sugar and place 2 inches apart on the prepared baking sheet.
4. Use your thumb to press into the center of each ball of dough. Spoon half a teaspoon of jam into each indentation.
5. Bake at 350 degrees for 12- 14 minutes or until the bottoms of the cookies are slightly brown. Remove the cookies from the oven and place on a cooling rack for 10 minutes.
6. Cookies can be stored in an airtight container in the refrigerator or at room temperature for up to 4 days. Baked cookies can also be stored in the freezer for up to 3 months.