Preheat the oven to 325°F and have ready a greased 9x13" casserole dish.

Combine the butter, milk, brown sugar, sweetened condensed milk, salt, cinnamon, and nutmeg in a saucepan over medium heat. Stir often and remove from the heat as soon as the butter has melted. Set aside to cool slightly.

In the meantime, cut the bread into 1" cubes and set aside.

In your largest mixing bowl, whisk the eggs until combined. Very slowly stream in the butter mixture, whisking all the while.

Add the cubed bread to the bowl and stir until the bread is coated in the custard. Fold in about ⅔'s of the bananas and transfer the mixture to the prepared dish.

Wedge the remaining bananas into the top into the bread pudding so the tops and sides are barely peaking through. Bake for 45-50 minutes. To check for doneness, gently poke down on the center of the casserole (using the back of spoon) and watch for any runny liquid to reveal itself. If you see any liquid rising up, the dessert is not yet ready and should continue to bake a few minutes longer. 

Set aside to cool and set up completely on a wire rack for about 45 minutes. Serve and enjoy!

Add the butter to a small saucepan over medium heat. As soon as the butter has melted, stir in the flour and whisk for about 1 minute.

Add the milk one big splash at a time, whisking well after each addition. Once all the milk has been incorporated, add the brown sugar, cream, and salt and stir.

Allow the mixture to simmer for about 5 minutes, or until slightly thickened, stirring occasionally. Add the vanilla and stir once more.

Pour the sauce over the bread pudding just before serving and enjoy!