Preheat the oven to 375°F and spray an 8 inch baking dish with cooking spray or rub with a little oil or butter. Put the baking dish on a baking sheet, and set aside.
Toss the whole wheat bread and the melted butter. Transfer to the prepared baking dish, and set aside.
Whisk together milk, eggs, mashed banana, Monk Fruit in the Raw, salt, cinnamon, nutmeg, and vanilla extract until completely combined. Pour over buttered bread in the baking dish. Try to make sure almost all of the bread is covered with the mixture.
Transfer to preheated oven and bake for 40-45 minutes, until a knife inserted in the center comes out clean. Take out of the oven and sprinkle with one tablespoon of brown sugar. Turn the oven to broil, and broil for 3 minutes until the sugar caramelizes and bread is lightly toasted. Let sit for 5 minutes before serving. Enjoy!