Line a 9x13" baking dish with vanilla wafers on bottom and sides.
Put a slice of banana on each wafer (About 3 and 1/2 bananas). Set aside.
Beat cream cheese until fluffy. Add mashed banana, vanilla and sweetened condensed milk.
Mix until combined. Add in milk and pudding mix. Beat at least 3 minutes to allow thickening.
Fold in 4 oz of whipped topping.
Carefully spread the mixture in the baking dish, over the wafers and bananas. Top with remaining whipped topping.
Refrigerate at least 4 hours, preferably overnight.
Top with remaining banana slices before serving.