1. Make the sauce: combine all sauce ingredients in a small bowl, stir until the sugar dissolves.
2. Pour 1/2 cup sauce (save remaining sauce for another use) in a zip-lock plastic bag; add in the chicken; seal bag and marinate chicken in the refrigerator for at least 30 minutes and up to 4 hours.
3. Preheat the broiler; remove chicken from marinade and arrange it on a broiler pan, skin side down (if the chicken still had skin).
4. Discard marinade.
5. Broil the chicken until brown and crispy, 8-10 minutes, then turn the pieces over and broil until almost cooked through, about 8 minutes longer.
6. Sprinkle the chicken with the sesame seeds and cook until the seeds turn golden brown and the chicken is done, 1-2 minutes longer.