Follow the instructions on the pudding mix to make pudding (this is what the milk is for) Then let set until it is a pudding consistency.
Cut up the banana into slices.
Layer Nilla wafers on the bottom of the container, a layer of pudding, a layer of banana, pudding, wafers, and then whip cream.
Notes
I make this in mason jars because I am the only one who eats it in my house so these are perfect servings. This makes about 4 containers. You can always add in more banana if you'd like.