Arrange chicken thighs in 15 1/2 inch by 10 1/2 inch jelly roll pan. Into cup, pour 1/4 cup hoisin sauce;use to brush both sides of thighs. Sprinkle with sesame seeds. Bake until juices run clear when thickest park of thigh is pierced with knife, 20-25 minutes.
Meanwhile, prepare dipping sauce: In microwave safe cup, combine chili sauce, ginger, vinegar, five spice powder, and remaining 2 tablespoons of hoisin sauce. Just before serving, heat mixture in microwave oven on High 45 seconds, stirring once. Serve chicken with dipping sauce.