In a bowl, toss together apple, brown sugar, caramel sauce and cinnamon, until well coated.
Grease a small ovenproof dish (or two small ramekins) with butter and transfer the apples to it. Top with cold butter. Set aside.
In another bowl, mix together the ingredients for the topping except the butter. Cut the butter into the mixture with a pastry cutter (or use your fingers). Refrigerate mixture for 15 minutes.
Spread chunks of the topping mixture over the apples and bake for 25-30 minutes or until the apples are done.
Serve the apple crumble with vanilla ice cream and more caramel sauce.