Heat 10- to 12-inch ovenproof skillet over medium heat; add 1 tablespoon of the butter. Add 2 sliced peaches, and sprinkle with brown sugar. Cook 3 minutes; stir peaches, and cook another 2 to 3 minutes or until caramelized and soft. Remove from the heat; add 1 teaspoon of the vanilla. Toss well, then remove and slide the peaches onto a plate. Rub remaining 1 tablespoon butter in warm skillet. Let skillet cool.