Prepare the Baking Dish: Preheat the oven to 350°F. Coat a 9 × 13-inch baking dish with nonstick cooking spray or line it with parchment paper.
Mix the Brownie Batter: In a mixing bowl, combine the German chocolate cake mix, 1/2 cup evaporated milk, 2 eggs, and 1/2 cup melted butter. Stir until the ingredients are thoroughly combined into a thick, sticky batter.
Form the Bottom Layer: Transfer approximately two-thirds of the brownie batter to the prepared baking dish. Spread and gently press it into an even layer. If the mixture is difficult to handle, use wet hands or a spatula lightly coated with cooking spray to help distribute it. Partially Bake the Base: Place the dish in the preheated oven and bake for 8 minutes. The brownie layer will continue baking later, so this initial bake prepares the base for the filling.
Melt the Caramels: While the brownie base bakes, place the unwrapped caramels and 1/3 cup evaporated milk in a small saucepan. Heat over medium heat, stirring as needed, until the caramels melt into a smooth mixture.
Add the Caramel Filling: Carefully remove the partially baked brownie layer from the oven. Gently spread the melted caramel mixture over the surface, distributing it as evenly as possible.
Add the Chocolate Chips: Sprinkle the 1 1/2 cups semi-sweet chocolate chips evenly over the caramel layer so the chocolate is distributed throughout the brownies.
Top with the Remaining Batter: Drop spoonfuls of the reserved brownie batter over the caramel and chocolate chips. Distribute the batter across the surface without worrying about covering every part completely.
Finish Baking: Return the baking dish to the 350°F oven and bake for another 20 minutes, or until the brownie layer is set.
Cool and Slice: Remove the brownies from the oven and allow them to cool before cutting. Once cooled, slice into 20 brownies and serve.
