1 stick butter, softened
1/4 cup brown sugar
1 egg yolk
1/2 tsp vanilla
1 cup flour
1/4 tsp salt
1/2 cup white sugar
your favorite jelly or preserves (I used my homemade blueberry)
Preheat the oven to 350 degrees. Mix thoroughly the butter, brown sugar, egg yolk and the vanilla. Work in the flour and salt until it becomes a dough consistency. Shape dough into 1 inch balls, I used a 1 inch ice cream scooper. In a small bowl, pour the white sugar. Dip the top into the sugar and place 1 inch apart on an ungreased baking sheet. Press thumb deeply into the center of each cookie. Repeat. I was able to get about 24 cookies out of the dough.
Bake for about 8 minutes. Remove from the oven. Fill the centers with your preserves. Return the cookies back into the oven and cook for another 10 minutes or until the cookies are slightly brown.
Immediately remove from baking sheet.