Blend together the sweetened condensed milk, pudding mix and cold water until combined. Transfer to a small bowl, cover with plastic wrap and refrigerate overnight, or for at least 4 hours.

When the pudding mixture has chilled overnight and is set. Start to beat the cold whipping cream using a whisk attachment in an electric mixer until the cream is fluffy and holds a stiff peak.

With a big spatula gently fold the pudding mixture into the whipped cream. Continue to fold and stir just until the pudding is combined.

Slice up the bananas, reserving 1/2 of a banana (in the peel) to add on top just before serving.

Begin assembly by adding a layer of the pudding whipped cream mixture to the bottom followed by a layer of Nilla wafer cookies, a few slices of banana, and another layer of the pudding. Repeat with cookies, bananas and pudding. Continue until you fill the serving dish or you run out of the ingredients for each layer.