Preheat oven to 350°F. Grease a 10-inch skillet with the softened butter.
Add the dry cake mix, 1 cup of evaporated milk, melted butter, and the walnuts to a medium size bowl. Mix everything together. The batter will be thick and kind of coarse looking.
Add half the batter to the prepared skillet, smooth it out evenly. Bake for 15 minutes.
While the brownies are baking, in a medium sauce pan melt the caramels while mixing in ⅓ cup evaporated milk. Stir until everything has combined to create a thickened sauce.
After baking for 15 minutes, remove the brownies from the oven and evenly sprinkle chocolate chips over the half-baked brownies.
Pour the caramel sauce evenly over the chocolate chips, smoothing it out creating a complete layer..
Spoon the remaining brownie batter on top of the caramel layer in dollops. There’s no need to smooth it out.
Bake for 25 minutes. Once done, allow it to completely cool before serving.
Notes
Melt the caramel low and slow. Keep the heat at medium-low and stir constantly. High heat scorches the caramel and makes it grainy.
Let it cool completely before cutting. The caramel layer is molten when the brownies come out of the oven. Give them at least 30 minutes to set up.
Grease generously. Caramel sticks to everything. A thick coat of softened butter on the skillet prevents a cleanup headache.
Use caramel bits to save time. Caramel bits work identically to individually wrapped squares and skip the tedious unwrapping step.
Make a caramel drizzle from the leftovers. Reserve a couple tablespoons of caramel sauce, thin it with leftover evaporated milk, and drizzle over the cooled brownies or vanilla ice cream.