1Blend: Combine bananas, cream, milk and puree until smooth. Add, sugar cornstarch, salt, and yolks, and blend again until totally smooth. Pour into a saucepan and set aside (no heat yet).
2Bloom Step 1: In a separate bowl, add 1 teaspoon gelatin and cover with water to activate gelatin. Be sure all the gelatin gets covered and there are no clumps (I stir with my finger). Let it bloom for 5 minutes until jelly-like consistency.
3Stovetop: Now, whisk the blended pudding over medium heat. As it heats, it will thicken. Bring to a boil, and continue to whisk vigorously for 2 minutes until starch is cooked out. When the surface boils with thick bubbles, then it is ready. The mixture will resemble a thick cement-like glue, with a color to match! Dump the contents of the saucepan back into the blender.
4Bloom Step 2: Microwave the bloomed gelatin until clear and warm (10 seconds).
5Blender: Add the butter, gelatin, and banana mixture back into the blender and blend. Add drops of yellow food coloring to brighten the mixture. Transfer the banana mixture to a heatsafe container and firm until it cools completely (at least 60 minutes).
6Mixer (whisk attachment): Whip the heavy cream until medium peaks (ribbons will form and you will know it is done). Fold the whipped cream into the banana pastry cream by 1/3rds. Each third, lightly fold the cream until thoroughly mixed in. Refrigerate until assembly.
7Assembly: Add cookie crumbs to the base of the mason jar, add fresh sliced bananas, then banana cream mixture, and lastly top with chocolate crumbs.