Tear bread into 1-inch pieces. Spread evenly on a jelly roll pan; place in a cool oven. Let stand overnight or until dried.
Combine egg and next 5 ingredients in a large bowl, beating with a whisk until well blended. Add dried bread and apple to egg mixture, tossing gently to moisten; let stand 30 minutes.
Preheat oven to 350°.
Spoon bread mixture into a 9-inch square baking dish coated with cooking spray. Bake at 350° for 40 minutes or until a knife inserted in center comes out clean. Let stand 15 minutes. Serve warm with ice cream and caramel sauce.