Creating Caramel Apple Crumble Bars is a simple process when you follow these steps:

1. Preheat Oven: Preheat your oven to 350°F (175°C). Grease a 9×13 inch baking dish or line it with parchment paper for easy removal.
2. Prepare Crust and Topping: In a large bowl, mix together the flour, oats, brown sugar, cinnamon, and salt. Pour in the melted butter and stir until crumbly. Reserve 1 cup of this mixture for the topping.
3. Press into Pan: Press the remaining mixture firmly into the bottom of the prepared baking dish to form an even crust.
4. Prepare Apple Filling: In another bowl, combine the diced apples, granulated sugar, lemon juice, cinnamon, nutmeg, and cornstarch. Mix until the apples are evenly coated.
5. Layer Filling: Spread the apple filling evenly over the crust in the baking dish.
6. Add Topping: Sprinkle the reserved crumb mixture over the apple filling, ensuring it’s evenly distributed.
7. Bake: Place the baking dish in the preheated oven and bake for 40-45 minutes, until the topping is golden brown and the apples are bubbly.
8. Cool: Once baked, remove the dish from the oven and allow it to cool for about 15-20 minutes.
9. Drizzle with Caramel: After cooling, drizzle the caramel sauce over the top of the bars.
10. Slice and Serve: Once cooled completely, cut into squares or bars and serve.

These steps will guide you in creating these incredible bars with ease and confidence.