Preheat oven to 350°F. Line a 9x13 baking dish with parchment paper, set aside.
Unwrap caramels and place in a saucepan with the evaporated milk. Heat over medium, stirring frequently, until caramels are fully melted and incorporated with the milk. (5-10 minutes)
Meanwhile, place butter in a large microwave safe mixing bowl, melt completely.
Add sugar, cocoa, vanilla and eggs. Whisk to combine well. Add remaining ingredients. Whisk until completely combined, but do not over mix.
Spread half of the brownie batter into prepared baking dish.
Spoon melted caramel over the brownie batter and use a silicone spatula to spread as best you can without mixing caramel into the brownie base.
Spoon the remaining brownie batter over the caramel layer.
Bake for 25 minutes or until a toothpick comes out clean. Allow to cool completely before cutting.
Brownies will keep at room temperature for 3-4 days or in an airtight container in the refrigerator for up to one week. Freeze for up to 3 months.
Notes
The brownie batter and the caramel sauce are both quite thick - spread the batters by spooning them across the pan so that spreading them is easier. Try not to disrupt the layers as you spread them so that the caramel stays sandwiched between the brownie layers.
Top the brownies with a drizzle of caramel and some mini chocolate chips if you wish.