Preheat the oven to 375°F, and lightly spray a 9 x 13-inch baking dish with cooking spray. Set aside.
In a large bowl, combine the flour, oats, brown sugar, baking soda, and salt. Add the butter, and use two forks or a pastry cutter to cut the butter into the dry ingredients until crumbly.
1 ¾ cups all-purpose flour, 1 cup quick oats, ½ cup light brown sugar, ½ teaspoon baking soda, ½ teaspoon kosher salt, 1 cup unsalted butter
Set aside 1 ½ cups of the mixture, and press the remaining into the bottom of the baking dish in an even layer. Spoon the apple pie filling over the crust and spread into an even layer. Set aside.
21 ounces apple pie filling
In a medium saucepan, combine the caramel squares and sweetened condensed milk over low heat. Stir constantly for about 5 minutes until the mixture is smooth and creamy. Carefully pour the caramel over the apple pie filling.
Add the chopped walnuts to the remaining crumb mixture and sprinkle it over the top of the caramel sauce.
1 cup walnuts
Bake for 25 to 30 minutes or until the bars are golden brown on top and the center is set. Allow them to cool completely before serving.
Notes
The calories listed are an approximation based on the ingredients in the recipe card and a serving size of 1 apple crumble bar. Actual calories will vary.Leftovers can be stored in a sealed container, in your fridge, for up to 3-days.For additional information and tips, please refer to the post.