In the body of a blender or food processor combine graham crackers, salt, and sugar. Pulse until the crackers have been completely smashed to crumbs. Add browned butter; stir well to combine. Press down into a 9-inch pie plate.
Place pie crust in oven and bake for 10 minutes, or until lightly golden.
Carefully remove pie crust from oven and place on a wire rack to cool. Once cool, sprinkle pecans evenly over the crust shell.
For the Bourbon Salted Caramel:
Pour cream into a small microwaveable ramekin; set aside.
In a small heavy pan combine the water and sugar. Bring mixture to boil over high heat, stirring constantly. At this point heat your cream on low in the microwave for 45 seconds, or until it's just simmering. *You can do this on the stove, but I find it easier to do it in the mic!
Once mixture has come to a boil, reduce heat to medium-high and boil for 6-8 minutes constantly stirring until the sugar has become deep, golden bronze color.
Remove pan from heat and stir in half of the warmed cream, stirring well to combine. Place pan back on the heat and add the reaming cream. Add salt and bourbon, stirring well to combine.
Allow mixture to come back to a boil over medium-high heat and cook for another 3 minutes, whisking constantly. Remove pan from heat, stir in butter, and cool for 15 minutes.
Pour caramel sauce over the pecans into the pie shell and place pie plate in the refrigerator to chill for at least 45 minutes.
For the Banana Cream Custard:
In a medium-sized sauce pan whisk together the sugar, corn starch, salt, egg yolks, and milks; beat well until smooth. Cook mixture over medium heat - stirring very frequently - until mixture thickens; 6-8 minutes. Remove pan from heat and whisk in butter, banana liqueur, and vanilla. Set aside to cool for 10 minutes, stirring frequently so skin doesn't form.
Remove pie crust from refrigerator. Layer sliced bananas over the caramel, completely covering it in a single layer. Pour custard over bananas. Cover the surface of the custard with saran wrap, and place in the refrigerator to cool for at least 4 hours.
When ready to serve, make the whipped cream!
For the Whipped Cream:
Beat the heavy cream, sugar, vanilla, and bourbon (if using) together until light and fluffy peaks form. Spread whipped cream over the top of the pie, and top with pecans and banana slices. Serve at once!