In medium sized bowl, whisk together the sweetened condensed milk and ice water until well combined. Then, add the pudding mix and stir until you no longer see any yellow spots from the powder. Cover and refrigerate for a minimum of 4 hours, preferably overnight.
After the pudding is set, whip the heavy cream in a stand mixer on low. When it begins to thicken, turn up the speed until stiff peaks form.
Once you have pointy peaks that don't fall over, take the bowl from the stand and use a spatula to gently fold about a third of the vanilla pudding at a time into the whipped cream. When no streaks of pudding are left the, now, vanilla cream will be a uniform pale yellow. Set aside.
Next, slice your bananas thinly and open the box of nilla wafers. Save some nilla wafers for garnish at the end before you start assembling.
Assemble by first spreading out vanilla cream mixture on the bottom of your container. Then cover it with a layer of banana slices and top the banana with a layer of wafers. Make sure each ingredient row is spread evenly with little-to-no overlap.
Repeat this step as many times as you can without running out of an ingredient or space in your container(s).
Depending on your level of OCD, finish the top with either some well-placed or artfully-crumbled wafers.
Cover tightly and allow to chill in the fridge before serving.