1 bunch scallions
1/4 cup hoisin sauce
1 tablespoon reduced-sodium soy sauce
1 tablespoon minced fresh ginger
1 tablespoon minced garlic
1 teaspoon Asian hot sauce, such as Sriracha, or to taste
1/4 teaspoon Chinese five-spice powder (see Tips)
4 bone-in chicken thighs (1 1/4-1 1/2 pounds total), skin removed, trimmed
4 chicken drumsticks (1-1 1/4 pounds total), skin removed, trimmed
1 1/2 teaspoons toasted sesame seeds (see Tips)