Preheat your oven to 350°F (175°C). In a mixing bowl, combine cold unsalted butter, granulated sugar, and all-purpose flour. Use a pastry cutter or your fingers to mix until it resembles coarse crumbs. Press this mixture into the bottom of a greased 9x9-inch baking dish. Bake for 15 minutes until the edges are lightly golden.

While the crust cools, prepare the caramel pecan layer by melting the caramel sauce in a saucepan over low heat, stirring constantly. Once melted, stir in the chopped pecans. Pour over the baked crust and spread evenly. Return to the oven and bake for an additional 10-15 minutes until bubbly.

Remove the dish from the oven and immediately sprinkle semi-sweet chocolate chips over the hot caramel layer. Allow the chips to soften, then spread the melted chocolate into an even layer across the caramel.

Let the bars cool completely at room temperature, about 1-2 hours. Once cooled, cut into squares using a sharp knife.