How to Make It
Preheat the oven to 350° and position a rack in the center of the oven. In a large bowl, whisk the eggs with the granulated and light brown sugars until smooth. Add the salt, vanilla and milk and whisk until the sugars are dissolved.
Spread the bread pieces in a 9-by-13-inch glass baking dish and pour the custard on top. Press the bread pieces into the custard and let stand, stirring occasionally, until the bread is evenly moistened, about 15 minutes. Fold in the chocolate chunks and smooth the top.
Cover the dish with buttered foil and set it in a large roasting pan. Transfer the roasting pan to the oven and pour enough hot water into the pan to reach halfway up the side of the baking dish. Bake the pudding for about 2 hours, until the center is completely set. Remove the baking dish from the water bath and let cool.
Serve the bread pudding warm with hot fudge and chocolate shavings, or refrigerate until very firm, at least 4 hours or overnight, and serve in scoops.