Prepare the Crust:
In a stand mixer or large bowl, cream together butter, shortening, and brown sugar for at least 4 minutes until light and fluffy.
Add flour, oats, salt, and baking soda; mix until well combined.
Set aside 2 cups of this mixture for the topping. Press the remaining mixture into an ungreased 13×9-inch baking pan.
Add the Apples:
Toss chopped apples with 3 tablespoons of flour until evenly coated.
Spoon apples over the crust in an even layer.
Make the Caramel Sauce:
Unwrap caramels and heat in a small saucepan over low heat with 3 tablespoons of butter.
Drizzle the melted caramel evenly over the apples.
Sprinkle the reserved oat mixture on top of the caramel and apples.
Bake:
Bake at 400°F (200°C) for 25–30 minutes, or until lightly browned.
Allow bars to cool completely before cutting.
