Preheat the oven to 350°F (175°C). In a mixing bowl, cream together the butter and sugar until smooth. Add the flour and salt, mixing until crumbly. Press the dough evenly into a greased 9x13-inch baking dish. Bake for 15 minutes or until lightly golden.

In a saucepan over medium heat, melt the butter and brown sugar, stirring constantly. Once it begins to bubble, stir in the heavy cream and pecans. Let simmer for 2 minutes, then pour the mixture evenly over the baked shortbread crust.

Bake the caramel pecan layer for another 15 minutes. Remove from the oven and immediately sprinkle chocolate chips over the top. Let them sit for 5 minutes to soften, then spread evenly with a spatula. Drizzle with vegetable oil for a glossy finish.

Allow the bars to cool completely at room temperature, then refrigerate for at least 1 hour to set. Once firm, slice into squares and enjoy!