BLEND mustard, ketchup, marmalade, soy sauce, onion and garlic in small bowl. Place chicken in resealable plastic bag; coat with 1/2 cup of the mustard mixture. Refrigerate chicken and remaining mustard mixture separately for at least 1 hour.
PREHEAT oven to 375°F. Arrange chicken on baking sheet. Bake 20 minutes; pour off any excess fat. Bake an additional 20 to 25 minutes or until cooked through.
HEAT remaining mustard mixture until warm; serve as a dipping sauce with hot chicken wings.