In a large bowl, whisk together cold milk, vanilla extract, and instant pudding until thickened.
Add sweetened condensed milk and mix until smooth and fully combined.
In another bowl, whip heavy cream until stiff peaks form.
Fold two-thirds of the whipped cream into the pudding mixture gently.
Add powdered sugar to the remaining whipped cream and fold to combine. Chill until needed.
In a trifle dish, layer vanilla wafers, sliced bananas, and pudding mixture.
Repeat layers until all ingredients are used, creating four layers.
Top with reserved whipped cream and decorate as desired.
Cover and refrigerate for at least 2 hours before serving.
This Easy Banana Pudding Recipe develops even better flavor after chilling.