In the bowl of your stand mixer, with paddle attachment fixed, combine the butter and sugar. Beat on medium speed until smooth and creamy, about 45 seconds. Mix in the vanilla extract. Mix again to combine. Beat in the salt and flour in 1/2 cup increments until a firm dough forms. Cover and chill the dough for 30 minutes.

Preheat your oven to 350 degrees F and line a 13x9 inch baking dish with foil. Place the dough in the prepared pan and press down with your finger tips until even. Bake the shortbread for 25 minutes or until light brown on top. Remove from heat and cool completely in pan on a wire rack.

Now prepare your caramel layer. Combine the dulce de leche and 1 tablespoon of butter in a small bowl. Place it in the microwave for 45 seconds to loosen up the caramel and stir. Pour the mixture on top of the cooled shortbread and spread evenly. Let cool slightly while you prepare your chocolate layer.

For the chocolate layer, bring the heavy cream, 1/2 cup of butter and corn syrup to a heavy simmer over medium heat. Remove from heat and stir in the chocolate chips and vanilla. Continue to stir until the chocolate has melted. Cool for about 5 minutes in the pan and then pour on top of the caramel layer. Spread to cover completely.

Cover the dish and place the chocolate caramel shortbread bars in the refrigerator until set, about 2 hours. Cut into bars and store in an airtight container for about a week. Enjoy!