Adjust oven rack to middle position and preheat to 350°. Butter an All-Clad 9-inch x 13-inch baking pan and set aside.

Slice croissants in half lengthwise and arrange half of them along the bottom of the buttered dish. Scatter the diced persimmons over the halved croissants. Top with the rest of the croissant halves. Whisk together milk, cream, sugar, and eggs and pour the milk mixture over the croissants. Allow bread pudding to sit for an hour, or up to overnight.

Place in oven and bake about 25 minutes. After the 20 minutes mark, brush the top with maple syrup and sprinkle the coarse salt sporadically and return to oven until golden brown on top and until the custard mixture is set and puffy, allow to sit for 15 minutes before serving.