Combine first 9 ingredients in small bowl; whisk spice rub to blend well.
Transfer 1 tablespoon spice rub to medium bowl; add butter and mix well (rub and seasoned butter can be made 2 days ahead. Cover separately. Chill butter. Bring butter to room temperature before using).
Sprinkle spice rub over both sides of chicken pieces.
Arrange chicken pieces on waxed-paper-lined baking sheets.
Cover chicken with more waxed paper and let stand at room temperature at least 1 hour and up to 2 hours.