In a small bowl, whisk the first 5 ingredients until blended; refrigerate until assembling., Brush peaches with butter. Grill, covered, on an oiled rack over medium heat or broil 4 in. from heat until lightly browned, 5-6 minutes, turning once. Grill rolls, uncovered, until lightly browned, 3-4 minutes, turning once. Cool slightly. Cut peaches and rolls into 3/4-in. cubes., In a large bowl, combine peaches and brown sugar; stir in bread cubes. Spoon into 12 well-greased, disposable aluminum muffin cups. Pour egg mixture into muffin cups., Grill, covered, over indirect high heat 12-15 minutes or until a thermometer reads at least 160°. Cool in pan 5 minutes before removing. Serve with caramel syrup and, if desired, whipped cream.