¾ Cup unsalted butter, softened
½ Cup Blueberry Sugar
2 egg yolks
1 ¾ Cup A.P. flour
½ Cup Blueberry Preserves
Preheat the oven to 375F. In a medium bowl, cream together the butter, Blueberry Sugar until light and fluffy, add 1 egg yolk at a time. Mix in flour a little bit at a time until a soft dough forms. Roll dough into 1 inch balls. If dough is too soft, refrigerate for 15 to 20 minutes. Place balls 2 inches apart onto ungreased cookie sheets. Use your finger or an instrument of similar size to make a well in the center of each cookie. Fill the hole with 1/2 teaspoon Blueberry Preserves.
Bake for 8 to 10 minutes in the preheated oven, until golden brown on the bottom. Remove from cookie sheets to cool on wire racks.
