Banana Crémeux 

Gelatin Mass
23 Weigh the gelatin with a small kitchen scale in a small glass and pour in the cool water. 
24 Stir to properly hydrate the gelatin and place in the fridge until ready to use. It will eventually look like a disk of jelly.
Caramelized Bananas
0 On medium heat, melt the butter in a medium-sized saucepan and sprinkle with brown sugar. Add the sliced ripe bananas and cook until the bottoms turn golden and caramelized (4-5 minutes). Flip over and repeat with other side. 
25 It's ok if they get a little mashed. Remove from heat and set aside.
Cream Infusion
1 In a medium saucepan heat heavy cream and scraped vanilla bean pod if using to a simmer. When you notice small bubbles forming, remove from the heat.
2 Spoon in the caramelized bananas and cover the saucepan with plastic wrap. Let sit at room temp for 30 minutes, then place in the fridge to steep for at least 4 hours. 
Crémeux
27 Place a medium sized bowl next to the stovetop for pouring the cooked créme.
14 Strain and Weigh Cream: Strain the banana pieces (and vanilla pod) from the cream, press well to get as much liquid as you can. Re-weigh the infused milk and cream, as the bananas will have absorbed a good bit. Add more cream to the mix as needed to get back to 425 grams total.
5 Heat the cream mixture and half of the sugar to a simmer over medium heat.
6 Meanwhile in a medium bowl, whisk the egg yolks and remaining sugar quickly with a bit of arm power until they look pale and foamy. 
7 Temper Eggs: Once the cream is simmering, remove from heat and pour about half into the bowl of the sugar whipped eggs. Whisk continuously as you pour in the hot liquid to temper the eggs.  
15 Pour everything back into the saucepan and return to medium heat. Have your thermometer ready, the mixture will heat back up quickly and you don't want to scramble the eggs.
8 Cook Custard: While continuing to whisk, heat the custard to 82℃ (180℉) Immediately remove from the stove and pour through a sieve into your separate bowl to prevent further cooking. 
16 Add Gelatin: Whisk in half of the gelatin mass at a time until dissolved. 
18 Chill: Place a sheet of plastic film directly onto the surface of the cremeux and refrigerate for at least 6 hours or ideally overnight to thicken. 
Whip and Use
19 Transfer chilled crémeux to a stand mixer fitted with a whisk attachment (or use an electric hand whisk). Whip on medium speed until thick and silky smooth.  This should only take about a minute. It will look separated at first, then quickly turn smooth.  
21 Now the crémeux is ready to use for piping, cake fillings, or just as pudding. The addition of gelatin has stabilized the mixture so it will hold its texture even outside of the fridge.