Preheat your oven to 375°F (190°C) and prepare a 9x13 inch baking pan lined with parchment paper.

In a large mixing bowl, combine melted butter, granulated sugar, vanilla extract, and salt until smooth. Gradually add all-purpose flour.

Press two-thirds of the crumble mixture into the bottom of the prepared pan.

In a separate bowl, toss thinly sliced apples with ground cinnamon. Spread apple filling evenly over the packed crumble base.

Drizzle salted caramel sauce over the apple filling.

Sprinkle remaining crumble mixture over the caramel-covered apples.

Bake for 40-45 minutes until topping is golden brown and filling bubbles.

Allow bars to cool completely in the pan on a wire rack before slicing.