Prep the recipe first because it'll need to sit a while. This is a great make ahead recipe.
In a bowl, mash the bananas. Then, whisk in the sugar, eggs, heavy cream, evaporated milk, the spices and the vanilla extract. Take the bread and cut it into cubes, then toss into the baking dish. Pour the custard over the cubed bread. Now, toss the bread in the custard to make sure all the pieces are covered. Cover the dish and place in the fridge for 2-3 hours.
Preheat the oven to 350℉.
Remove the top from the baking dish, then place in the preheated oven for 30-40 minutes. The banana bread pudding is done when you can insert a toothpick in the center and it comes out clean.
While the dish is baking, make the sauce on the stove top. Add in the butter first on medium heat. Once the butter has melted, pour in the sugar and whisk. Lastly, pour in the mixture of milk and cornstarch and continue to stir until it's thickened. Once it's thick, remove from the heat, then stir in the vanilla extract.
When the banana bread pudding is ready, remove from the oven and pour on the topping. Allow everything to cool before serving, enjoy.