Meanwhile, heat gas or charcoal grill. In small bowl, mix brown sugar, cinnamon and 2 tablespoons butter; set aside. Carefully brush oil on grill; place peach haves, cut sides down, on grill over medium-high heat. Cook uncovered about 5 minutes until peaches start to soften. Turn peaches over; spoon brown sugar mixture into centers. Cook 5 minutes longer; remove from grill.