Place flour and salt in a food processor; pulse until blended. Add butter and sesame seeds; pulse until blended. With processor running, add 1 tablespoon water and vinegar; process until mixture forms a ball, adding more water, if needed. Shape dough into a log; cover and chill 30 minutes.
Place 1 1/2 teaspoons of dough into each ungreased miniature (1 3/4") muffin cup, pressing gently up sides of cup. Prick sides and bottom of dough with a fork. Bake at 400° for 10 minutes or until edges are lightly browned. Cool in pan on wire racks 5 minutes. Remove from pans, and cool completely on wire rack.