In a medium bowl, combine vanilla wafer crumbs and melted butter until the mixture resembles wet sand.
Press the crust mixture firmly into the bottom of a 9x13-inch dish to create an even layer.
Place the crust in the refrigerator while preparing the filling layers.
In a large mixing bowl, beat the softened cream cheese until smooth and creamy.
Add powdered sugar and continue mixing until fully combined.
Fold in the whipped topping gently until the mixture becomes light and fluffy.
Spread the cream cheese mixture evenly over the chilled crust layer.
In another bowl, whisk together the instant banana pudding mix and cold milk for about 2 minutes until thickened.
Arrange sliced bananas evenly over the cream cheese layer.
Add a layer of vanilla wafers over the bananas.
Spread the banana pudding evenly over the cookie and banana layers.
Top the dessert with the remaining whipped topping and spread smoothly.
Garnish with extra vanilla wafers, banana slices, and crushed cookie crumbs.
Refrigerate for at least 4 hours, or overnight, until fully chilled and set.
Slice and serve cold for the best flavor and texture.