Bake biscuits as directed on bag; place on wire rack. Brush tops with melted butter. In small bowl, mix sugar and cinnamon; sprinkle over biscuits.
In 1-quart saucepan, heat caramel topping over medium heat just until warm. Stir in apple; cook 2 to 3 minutes, stirring occasionally, until apple is crisp-tender.
Split warm biscuits; fill and top with apple mixture. Top with whipped topping.