Step 1

In a large bowl, whisk together the pudding mix and milk until combined.  Set aside to thicken.

Step 2

Peel and slice the bananas.  Place them in a medium bowl and toss with the lemon juice to prevent browning.

Step 3

Fold the whipped topping into the pudding.  Add the bananas, marshmallows, and vanilla wafers.  Fold together.  Serve immediately or refrigerate for a a few hours if you prefer softer cookies.