In a large bowl, pour in the sweetened condensed milk and cold water. Use a whisk to combine them thoroughly. Make sure the mixture is smooth before moving to the next step.

Slowly sprinkle the instant vanilla pudding mix into the milk mixture. Whisk it constantly for about two minutes. Once it starts to thicken, put it in the fridge for 5 minutes.

In a separate chilled bowl, pour the heavy whipping cream and vanilla extract. Use an electric mixer to beat the cream on high. Stop once you see stiff, firm peaks form.

Take the pudding out of the fridge. Gently fold half of the whipped cream into the pudding using a spatula. Then, fold in the rest. Do this slowly so the air stays in.

Grab your baking dish or trifle bowl. Place a single layer of Nilla Wafers at the bottom. Make sure they cover the base completely. This creates the "crust" of your dessert.

Peel and slice your bananas into rounds. Lay half of the banana slices over the cookies. Try to spread them out evenly so every bite has some fruit in it.

Pour half of your creamy pudding mixture over the banana layer. Use your spatula to smooth it out to the edges. Ensure all the bananas and cookies are covered.

Add another layer of cookies on top of the pudding. Follow this with the remaining banana slices. Finish by pouring the rest of the pudding mixture over the top.

Crush a few extra cookies and sprinkle them on top for decoration. Cover the dish with plastic wrap. Let it chill in the fridge for at least 4 hours.