To prepare the raisins, combine them with the rum in a small saucepan and bring to a boil over high heat. Remove from the heat, cover the pan, and set aside to absorb the liquid and come to room temperature. Drain the raisins and discard the alcohol (or reserve it for another culinary use).

To make the caramel layer, have your baking dish handy.

Put the sugar in a heavy-bottomed, light-colored medium saucepan. Add 120 grams (½ cup) water and stir with your finger to combine. Bring to a boil over medium-high heat without stirring, using a wet pastry brush to remove any sugar granules that may be stuck to the sides. Continue boiling, tilting, and swirling the pan so the sugar cooks evenly, until it is a dark mahogany color and is just beginning to smoke, 9 to 12 minutes. Remove the pan from the heat and pour the caramel into the baking dish. Tilt the dish so the caramel coats about 1 inch up the sides. Set aside for the caramel to set while you prepare the rest of the bread pudding.

To prepare the bread, adjust the oven racks so one is in the top third and the other is in the bottom third of the oven and preheat the oven to 350°F. Line two large baking sheets with parchment paper. Locate a roasting pan that the baking dish will fit inside of with at least a few inches of space around the dish and set both aside.

Cut the bread loaves in half through the top, and pull the bread out of the crust in 2- to 3- inch chunks. You want the bread chunks to be consistent in size but not in shape; their beauty is in their irregularity. (Reserve the crusts for another use, such as to make bread crumbs.)

Lay the bread chunks in an even layer on the baking sheets and put a baking sheet on each rack in the oven and bake until they are crunchy (but not hard) in places and soft in others, 12 to 15 minutes, switching racks and rotating the baking sheets front to back halfway through the baking time so the bread toasts evenly. Remove the bread from the oven. Leave the oven on.

Place the butter in a small saucepan or skillet with a light- colored bottom to make golden butter. Warm the butter over medium heat until it melts and begins to bubble, swirling the pan occasionally. Cook the butter, swirling often so it cooks evenly, until it is golden and the milk solids are caramel colored, 3 to 6 minutes. Remove from the heat and pour the butter into a large wide bowl. Add the sugar and cinnamon and stir to combine.

Add the toasted bread chunks to the bowl with the butter and toss with your hands for 1 or 2 minutes to coat the bread with the butter and cinnamon-sugar. (The bread will not absorb all the butter; excess butter will pool at the bottom of the bowl.) Lift the bread chunks from the bowl and place them on a large baking sheet. Clean the bowl, reserving the leftover butter for another use where cinnamon and sugar are welcome or discarding it. Return the bread to the bowl.

To make the custard, whisk the whole eggs, egg yolks, sugar, vanilla, and salt together in a large bowl. Fill a medium saucepan with water. Place the bowl on top of the saucepan. (The weighted saucepan anchors the bowl, so it remains stable when you whisk ingredients in it.)

Combine the milk, cream, and cinnamon sticks in a large saucepan and bring to a simmer over medium heat. Remove from the heat and discard the cinnamon sticks.

Slowly add the hot milk and cream to the bowl with the egg mixture, stirring constantly with a whisk and adding it gradually to prevent the hot cream and milk from cooking the eggs. Set aside for about 20 minutes to infuse the custard with the cinnamon. Pass the custard through a fine-mesh sieve to strain out any remaining bits of cinnamon sticks and any lumps that may have formed in the custard.

Pour 3 cups of the custard over the bread: toss gently, and set aside for about 5 minutes, tossing occasionally so the bread absorbs the custard evenly.

To finish the bread pudding, stir the cinnamon, nutmeg, and anise seed together in a small bowl. Bring a kettle of water to a boil to fill a roasting pan and make a bain-marie, or water bath.

Place the baking dish with the caramel in front of you, pour in 1 cup of the custard and scatter ¼ cup of the raisins over the caramel. Building the bread pudding in three layers, lay one-third of the bread chunks in the dish, pour in one-third of the remaining custard, and scatter ¼ cup of raisins over the bread. Build a second layer using half of the remaining bread chunks and half of the remaining custard and scatter ¼ cup of raisins over the top. Add the remaining bread chunks, mounding them so the center of the pudding has a slightly domed shape, and pour over the bread as much of the remaining custard to fill the baking dish to ¼ inch from the top (discard any remaining custard). Scatter the remaining raisins and the spice mixture over the top of the pudding and place the bread pudding in the roasting pan.

Pull out the center rack of the oven and place the roasting pan on it. Carefully pour enough boiling water into the roasting pan to come halfway up the sides of the baking dish, taking care not to get any water on the bread pudding. Gently slide the oven rack back in and bake the bread pudding until it is set around the edges but is still slightly runny in the center, 1 hour 20 minutes to 1 hour 30 minutes. To test for doneness, squeeze on a chunk of bread; if liquid comes out, it needs more time.

Increase the oven temperature to 450°F and bake the pudding until the top is well browned and crispy, another 10 to 15 minutes.

Remove the roasting pan from the oven and let the bread pudding cool to room temperature in the bain-marie. Remove the bread pudding from the bain-marie and dry the bottom of the baking dish. Refrigerate the bread pudding overnight, uncovered, to chill. (You can serve the bread pudding still slightly warm from the oven, but I think it is at its best reheated after it has been chilled.)

To serve, adjust an oven rack to the center position and preheat the oven to 350°F.

Remove the bread pudding from the refrigerator and place it in the oven until it is warmed through but not piping hot, 30 to 45 minutes. Remove from the oven and serve slightly warm.