Combine pudding ingredients in large mixing bowl and whisk until well combined and thickened. Set aside.
In stand mixing bowl, add cold milk and begin to to whisk on MED speed. when starts to thicken, slow speed down and add powdered sugar. Continue on MED until stiff peaks form.
Slowly and gently fold (with spatula) about 2/3 of whipped cream into pudding until completely integrated (no white streaks). Place rest of whipped cream into piping bag, set both bag and pudding bowl in fridge while you work on rest of dessert.
Make crumbles. I use food processor to quickly crumble the wafers to a medium fine granularity. In a large mixing bowl add crumbled wafers, melted butter, extract and salt. With fork, mix until completely combined and you have a wet sand like consistency. On a large sheet tray lined with parchment paper or Silmat, spread crumbles in even layer. Bake in oven 10-12 minutes or until just starting to brown. Remove from oven and let cool.
Bananas Foster
Slice bananas lengthwise and then slice into 1/8" half moons.
Heat large skillet over MED heat. Add butter. When melted, add sugar and mix to a slurry. Add Bananas and sautee in mixture until just softened. 2-3 min. Add rum and flambee alcohol off, reducing for another 2 min. Remove from heat and allow to cool.
Build your cups
In clear 8oz cups or small Mason jars work well too. Place 1 TBSP crumbles into bottom. Then 1 TBSP cooked and cooled bananas on top. Then fill 2/3 of the cup with pudding. I like to use another piping bag for this as well - makes it so much easier and cleaner! Then dust the top of that layer with more crumbles.
Refrigerate at least 1 hour before serving. Pipe final layer of whipped cream on top of that and finish with another light dusting of crumbles just before serving.