In a large mixing bowl, whisk together the instant vanilla pudding mix and cold milk until smooth and thickened, about 2 minutes.
Add the sweetened condensed milk and vanilla extract, stirring until fully combined for a silky pudding base.
In a separate bowl, whip the heavy cream with a pinch of salt until soft peaks form.
Gently fold the whipped cream into the pudding mixture to create a smooth and creamy filling.
In a trifle dish or glass bowl, layer vanilla wafers, banana slices, and the pudding mixture.
Repeat the layers until all ingredients are used, ending with a pudding layer on top.
Cover and refrigerate for at least 4 hours or overnight.
Before serving, top with extra banana slices and crushed vanilla wafers if desired.
