Preheat oven to 350 degrees. Spread 1 tablespoon butter in a 10 inch cast iron skillet or baking dish.
Peel, core and slice the apples and place into a medium bowl. Toss with sugar, flour and cinnamon and pour into the skillet or baking dish. Drizzle 1/4 cup caramel over apples.
In a medium bowl add the flour, brown sugar, salt, cinnamon, oats and cold butter. Mix using a fork or your hands until crumbly. Spread evenly over apples.
Bake 30-40 minutes or until apples are tender and caramel is bubbly.