CHICKEN

2 tablespoons packed dark brown sugar
1 1/2 tablespoons kosher salt
1 1/2 teaspoons onion powder
1 1/2 teaspoons garlic powder
1 1/2 teaspoons paprika
1/4 teaspoon cayenne pepper
6 pounds bone-in chicken pieces (split breasts and/or leg quarters)

SAUCE

1 cup ketchup
5 tablespoons molasses
3 tablespoons cider vinegar
2 tablespoons Worcestershire sauce
2 tablespoons Dijon mustard
1/4 teaspoon pepper
2 tablespoons vegetable oil
1/3 cup grated onion
1 garlic clove, minced
1 teaspoon chili powder
1/4 teaspoon cayenne pepper