Procedures

1. 1

   In a small bowl, whisk together almond flour, flour, and salt.

2. 2

   In a large bowl, beat together butter, light brown sugar, and sugar with an electric beater until light and fluffy. Beat in vanilla and egg yolk.

3. 3

   Mix in flour mixture until just incorporated. Wrap dough in plastic wrap and chill in refrigerator for 30 minutes.

4. 4

   Preheat oven to 325 degrees. Roll dough in 1 inch balls. Use your thumb to press a deep indent in the center of each ball. Bake until golden, about 15 minutes.

5. 5

   Let cookies cool on a wire rack. Fill each indent with blueberry preserves.