In a large mixing bowl, whisk together the pudding mix, milk, and vanilla extract until smooth and thickened—about 2 minutes.
Fold in the whipped topping gently using a rubber spatula until fully combined and fluffy.
Layer banana slices in the bottom of the prepared pie crust.
Spoon the pudding mixture over the bananas and spread evenly.
Top with crushed vanilla wafers.
Chill in the refrigerator for at least 3 hours, or until set.
Slice and serve cold with extra banana slices or whipped topping if you're feeling fancy.