Combine the contents of vanilla instant pudding mix and milk in a mixing bowl. Mix it until firmly set. Add the condensed milk and continue to mix until well-blended. In batches, gently fold in the cooling whip into the mixture until smooth and everything is all mixed together.
Cover the bowl and store in the fridge to set overnight.
Assemble the layers the following day. Layer the wafer cookies, bananas, and pudding mixture in 3 equal parts.
Vanilla wafer cookies first.
Sliced bananas next.
Then some of the pudding mixture. Repeat the process 2 more times.
Let it chill in the fridge for 3-4 hours.
Spread the remaining cool whip on top and sprinkle the reserved crushed wafer cookies on top.