Preheat oven to 350° F. Spray 13 x 9-inch baking pan with nonstick cooking spray. Set aside.
In a large bowl, combine brownie mix, eggs, oil, and water and mix thoroughly according to brownie package directions. Stir in mini morsels. Set aside.
In a medium-sized microwave safe bowl, heat evaporated milk for 15 seconds, or until warm. Add dulce de leche and stir until combined.
Pour half of the brownie batter into prepared pan. Place dollops of the dulce de leche mixture over batter in pan. Using a knife, swirl the dulce de leche to create ribbons in batter. Pour remainder of batter on top and spread evenly. Bake brownies for 22-25 minutes, following brownie package directions.
Remove pan from oven and let cool to room temperature on a cooling rack.