In a large bowl, whisk together the sweetened condensed milk and the cold water until fully combined.
Using an electric mixer on low speed, gradually add and blend one box of pudding mix into the sweetened condensed milk mixture, and whisk until it is smooth.
Cover the pudding mixture with plastic wrap and refrigerate for at least 3 hours, or overnight.
In a large bowl, beat the cold heavy cream until stiff peaks form, about 3-4 minutes. Once the cream begins to thicken, keep beating on high speed until stiff. Blend in the vanilla extract.
Next, fold the chilled pudding mixture into the whipped cream, and stir gently until fully combined.
After that, add 5 tablespoons of dry vanilla pudding, from the remaining package, and beat until you get a fluffy consistency.
Assemble the dessert in a clear glass trifle bowl by adding ⅓ layer of the pudding, top with nilla the wafers, and ⅓ of the bananas. Repeat this again, then finish the dessert with a heaping layer of pudding.
Make sure all of the bananas are completely covered with the pudding mixture or they will turn brown more quicker.
After assembling, chill the trifle for at least 4 hours so the vanilla wafers will soften.
Garnish with nilla wafers crumbs and sliced bananas right before serving.
