Preheat the oven to 350 degrees Fahrenheit. Spray a 9 x 13 x 2-inch baking pan with nonstick cooking spray. Line the pan with parchment paper, leaving a 1-inch overhang on either side for easy removal from the pan, if desired.
Add the unwrapped caramels and ⅓ cup of evaporated milk to a small saucepan and heat over low heat. Stir until all of the caramels have melted and completely incorporated into the evaporated milk, about 5 minutes. Remove from the heat and set aside to cool slightly.
Meanwhile, combine the cake mix, remaining ⅓ cup of evaporated milk, melted, butter, and flour in a large bowl until fully combined. Press half of the batter evenly into the bottom of the prepared pan with your fingers. It may look thin, but it will puff up! Bake for 6-8 minutes.
Remove the baking pan from oven and sprinkle the chocolate chips evenly over the hot brownie batter. Top evenly with the slightly cooled caramel.
Crumble the remaining brownie batter over the top of the caramel and bake for an additional 18-20 minutes.
Remove the brownies from the oven and let them cool completely, until the caramel is set. If needed, you can chill the brownies in the fridge to speed this up.
Notes
Storage Instructions: Store in an airtight container at room temp, or refrigerate for firmer caramel (up to 7 days). To freeze, wrap tightly in plastic and foil, and freeze for up to 3 months. Thaw at room temperature before serving.