Step 1

Preheat oven to 350°F. Spray a 13- x 9-inch baking pan with baking spray, and line pan with parchment paper.

Step 2

Prepare the Crumble: Stir together flour, oats, brown sugar, pecans, cinnamon, and baking soda in a large bowl until combined. Stir in melted butter until combined.

Step 3

Firmly press 4 cups of the Crumble mixture into bottom of prepared pan to form a crust; reserve remaining Crumble mixture for use in Step Bake crust in preheated oven 10 minutes.

Step 4

Meanwhile, prepare the Filling: Fold together apples, brown sugar, flour, and cinnamon until combined. Spoon over warm crust, and firmly pat apples down to create an even layer. Sprinkle with remaining Crumble mixture.

Step 5

Bake at 350°F until crust is golden brown and apples are tender, 55 to 65 minutes, covering loosely with aluminum foil as necessary to prevent excess browning. Let cool completely before slicing, about 3 hours. Drizzle with salted caramel topping or sauce, if desired.