Prepare brownie mixes according to package directions and pour batter into a greased 9 by 13 pan. Bake the brownies and cool completely. Once the brownies are cool, cut into small 1 inch squares.
In a large bowl, combine pudding mix, whole milk, and sweetened condensed milk. Mix until smooth, then fold in 8 ounces whipped topping until no streaks remain.
In a trifle bowl or large glass bowl, place half of the brownies into the bottom of the dish. Layer half of the pudding mixture directly onto the brownies. Next, add half of the remaining container of whipped topping. Repeat layers. Cover and refrigerate 3-4 hours before serving.
Notes
I prefer making my brownies and whipped cream, but either way is still delicious.