Mix first 4 ingredients in small bowl to blend. Season with salt and pepper.
Grill corn until beginning to soften, turning occasionally, about 5 minutes. Brush all over with hoisin butter; continue to grill until corn is tender, brushing occasionally with more hoisin butter, about 5 minutes longer.
Transfer to platter; brush with more hoisin butter. Sprinkle with cilantro and serve.