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.
Early in day, sprinkle spicy rub over both sides of chicken pieces. Marinate in the in teh refrigerator for several hours.
Reserve 4 tablespoons seasoned butter. Spread remaining seasoned butter on 1 side of baguette slices. Place bread slices on platter and cover.
Place chicken on grill, skin-side up. Grill 20 minutes. Turn chicken over. Grill until skin is deep golden brown, about 15-20 minutes. Turn chicken again and grill, skin-side up, until thoroughly cooked and no red remains.
Transfer chicken to platter. Brush chicken with reserved 4 tablespoons seasoned butter.
Grill bread until just golden, about 2 minutes per side. Arrange toasts around chicken and serve.