In a large bowl, mix together cake mix, ⅓ cup evaporated milk, and melted butter. Mix together until combined.
Use cooking spray to grease a 9x9 inch square baking pan. Press half the mixture into the pan. Bake for 8 to 10 minutes. Remove pan from oven and set aside.
Meanwhile, in a double boiler (or a small pan set over a saucepan of boiling water) melt caramels with the additional ½ cup evaporated milk. When melted, pour over pre-cooked brownie base. Sprinkle chocolate chips as evenly as you can over the caramel.
Place remaining uncooked brownie dough on a sheet of wax paper. Use your hands to press it into a large square a little smaller than the pan. Pick up the whole sheet of way paper and flip over the brownie layer on top of the caramel and chocolate chips. Remove the wax paper from the top of the brownie layer.
Bake for 20 to 25 minutes. Remove from pan and allow to cool to room temperature, then cover and refrigerate for several hours. Before serving, sift powdered sugar on the brownies. Cut into twelve squares and remove from the pan.
Recipe by 2 Sisters 2 Cities at http://www.2sisters2cities.com/2012/11/caramel-layered-brownies/