Preheat oven to 350 degrees. Prepare a 9x13-inch pan by lining it with a parchment paper sling with the paper hanging over the edge so that you can lift the brownies out after they have finished cooling for easy cutting or just spray with pan with cooking spray.

Place the unwrapped caramels in a large glass bowl along with ½ cup of evaporated milk and set over a pan of simmering water. Do not let the water touch the bottom of the bowl. Stir occasionally until the caramels are completely melted and combined with the evaporated milk. It may take a while but you can work on the brownie batter while the caramels are melting.

While caramels are melting, combine the cake mix, softened butter, and ⅓ cup of evaporated milk in a large bowl and mix together using a large spoon until it all comes together. This brownie batter will be very thick, more like cookie dough.

Divide the brownie batter in half and crumble or press half of the mixture into the bottom of the prepared 9x13-inch pan, then bake in the preheated oven for 8-10 minutes until slightly set.

Remove from the oven and immediately sprinkle with ½ cup of chocolate chips. Pour the melted caramel over the top, then crumble the rest of the brownie batter on top of the caramel or use your fingers to make small discs of brownie batter to gently lay on top of the caramel layer. It's okay if some of the caramel peeks through.

Return the brownies to the oven and bake for an additional 20-25 minutes, until the top is set. Remove from oven and allow the brownies to cool to room temperature. Cover with plastic wrap and refrigerate brownies for several hours until they are well-chilled. When ready to serve, dust generously with powdered sugar and cut into small rectangles.