Direction

1. Grease a 9x13-inch baking dish with 1 tablespoon of butter; place remaining butter in a saucepan over low heat to melt. Spread bread cubes out in the greased pan and drizzle melted butter over top.
2. Place walnuts into a dry skillet over medium-low heat; cook and stir until walnuts turn a light golden brown and give off a toasted fragrance, about 2 minutes. Watch carefully so they don't burn. Remove from heat and transfer walnuts into a bowl immediately to cool. Set walnuts aside.
3. Beat eggs lightly in a large mixing bowl, just to break yolks, and mix in condensed milk, coconut milk, cream, brown sugar, vanilla, cinnamon, nutmeg, allspice, and salt. Whisk to thoroughly combine until smooth. Stir in mashed banana and 3/4 cup toasted walnuts. Pour the banana mixture evenly over bread cubes and push bread cubes into the mixture to coat well with the custard. Sprinkle with remaining 1/4 cup toasted walnuts. Cover the dish with plastic wrap and refrigerate, 8 to 12 hours.
4. Preheat the oven to 350 degrees F (175 degrees C). Remove plastic wrap and cover the dish with foil.
5. Bake in the preheated oven for 15 minutes, then remove the foil and return to the oven until the top is browned and the edges are pulling away from the pan, about 45 more minutes. Allow to cool before serving.