Preheat oven to 350-degrees. Line an 8-inch bake pan with parchment paper or foil and spray the sides and bottom of the pan with baking spray. Set aside.

In the bowl of a stand mixer, affixed with the paddle attachment, add the butter and both sugars. Mix on medium-high speed until the mixture is light and fluffy. Add the egg and vanilla extract. Mix until fully combined.

Change the mixer to low speed and add the flour, salt, cornstarch, baking soda and baking powder. Mis until just combined. Remove the bowl from the mixer and use a rubber scraper to ensure all the ingredients are fully incorporated. Fold in the chocolate chips.

Press half of the cookie dough into the prepared pan and evenly distribute the dough into the pan (wet your fingers slightly to push the dough evenly into the pan). Add the caramel in an even layer over the bottom layer of cookie dough. Drop teaspoon sized pieces of remaining dough on top of the caramel layer, trying to cover as much of the caramel as possible.

Bake the cookie bars in a 350-degree oven for 28-32 minutes or until the edges are a light brown and the middle doesn't jiggle. Do not over bake though. Remove from the oven and set on a wire rack to cool completely.