In a small bowl, combine graham cracker crumbs and butter. Press gently onto the bottom of 12 paper-lined muffin cups. In another small bowl, beat the cream cheese, sugar and vanilla until smooth. Add egg; beat on low until just combined. Spoon over crusts. Bake at 350° for 15-16 minutes or until center is set. Cool for 10 minutes before removing from pan to a wire rack to cool completely. Refrigerate for at least 1 hour. Remove paper liners; top each cheesecake with 1 teaspoon jam.