Prepare barbecue (medium-high heat). 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; serve.
*Available in the Asian foods section of many supermarkets and at Asian markets.