Preheat oven to 325°. Butter a 9- by 13-inch baking dish. Cut bread into 1-inch (bite-size) cubes, toss with coconut flakes and arrange evenly into the baking dish.
In a large bowl, whisk together eggs lightly (to break the yolks), add in coconut milk, milk and vanilla. Beat until all ingredients are well combined.
Pour milk mixture over bread and allow for it to soak for at least 15 minutes (this can be done the night before!)
Bake uncovered about 40 minutes. If it starts to get too dark on top, cover with foil. When done, it will be golden brown, puffy and have a slight jiggle in the center.
Serve warm, room temperature or cold. Top with your favorite syrup, more coconut flakes and fresh sweet mango.