In a large mixing bowl, combine the sweetened condensed milk, cold water, and instant vanilla pudding mix. Whisk vigorously for about 2 minutes until the mixture is smooth and thickened.

Cover the bowl and refrigerate the pudding mixture for 5 minutes, allowing it to set to the perfect creamy consistency.

While the pudding chills, take a separate mixing bowl and pour in the heavy cream. Using an electric mixer, beat the cream on medium speed for about 3-5 minutes, or until soft peaks form.

If desired, add sugar and vanilla extract while whisking. The cream should be fluffy and light.

Retrieve the chilled pudding mixture from the refrigerator. Gently fold in the whipped cream using a spatula until no visible streaks remain.

In a trifle dish, start building your layers: layer with Nilla wafers, then bananas, then pudding. Repeat until all ingredients are used, finishing with pudding on top.

Cover and refrigerate the assembled pudding for at least 4 hours, ideally overnight.

Serve chilled, ensuring everyone gets a portion of the delicious banana, creamy pudding, and crunchy wafers.