Cream butter, cream cheese and sugar until light and fluffy. Beat in vanilla. Gradually beat in flour. Divide dough into four portions. Shape each into a disk; wrap in plastic. Refrigerate until firm enough to roll, about 2 hours., Preheat oven to 375°. On a floured surface, roll each portion of dough to 1/8-in. thickness. Cut with a floured 2-in. round cookie cutter. Place half of the circles onto ungreased baking sheets. Place 1/2 teaspoon preserves in the center of each circle; top with remaining circles and press edges lightly with a fork to seal. Cut slits in the top of each cookie. Bake until edges are light brown, 7-9 minutes. Remove from pans to wire racks to cool.