In a large bowl, whisk together the milk and vanilla pudding mix until smooth and thickened.
Add the sweetened condensed milk and mix until well combined.
Fold in the whipped topping gently until fully incorporated.
Layer vanilla wafers on the bottom of a serving dish, followed by banana slices, and a layer of pudding mixture.
Repeat layers until all ingredients are used, ending with a layer of pudding on top.
Refrigerate for at least 2 hours before serving.