*If New Orleans-style French bread is not available, you can get similar results using a sugarless, natural-yeast white bread with a low gluten ?content and a thin crust.
Instructions:
Scatter the bread cubes in a 9-by-13-inch glass baking dish. Set aside.
In a heavy 3-quart saucepan, combine the cream, milk, and 1½ cups sugar. Cut the piece of vanilla bean in half lengthwise, and scrape the tiny beans into the cream mixture. (Discard the scraped bean pod or add it to granulated or powdered sugar to make vanilla sugar.)
Bring the cream mixture to a simmer over medium-high heat, whisking constantly until the sugar dissolves, then whisking occasionally.
Add the chocolate chips and continue cooking until the chocolate is melted, about two minutes more, whisking frequently and being sure to scrape the pan bottom clean as you whisk. Remove from heat.
In a large mixing bowl, lightly whisk the eggs until frothy. Very slowly add the chocolate mixture to the eggs, whisking constantly so the eggs don’t curdle. Pour this custard mixture over the bread. Let the custard sit until cool enough for you to put your hands in it, about 10 minutes.
Once the custard is cool enough, toss the bread cubes with your hands, squeezing the cubes in the liquid to make sure all are well saturated. Cover and refrigerate overnight. About three hours before baking the pudding, remove the pan of pudding from the refrigerator, and evenly sprinkle the top with ¼ cup sugar. Let the pudding sit at room temperature for 45 minutes. Meanwhile, preheat the oven to 300°F.
Once the pudding has sat 45 minutes, seal the baking dish with aluminum foil. Bake the pudding until a toothpick inserted in the center comes out almost clean and the pudding looks solidified with no puddles of liquid on the surface, about two hours. Once done, it will also start developing a few small, shallow cracks on top and there will be an irresistible smell of chocolate emanating from the oven.
Remove the pudding from the oven and let it sit for 15 minutes at room temperature before serving.