Preparation Position a rack in the middle of the oven and preheat to 325°F. Butter a 9- by 13- by 2-inch rectangular ovenproof dish. Spread the remaining butter on one side of each bread slice. Arrange the bread slices, buttered side up, in one layer on the bottom of the prepared dish. Sprinkle with the raisins and set aside. In a large saucepan, combine the milk, heavy cream, and salt. Using the blade of a small, sharp knife, scrape the seeds from the vanilla beans into the mixture; add the scraped vanilla beans. Place the pan over moderate heat and bring to a boil. Remove from the heat. In a large bowl, whisk together the eggs and sugar until pale yellow, about 1 minute. Whisk about 1 cup of the hot milk mixture slowly into the egg mixture to raise the temperature without cooking the eggs. Gradually whisk in the remaining milk mixture, whisking until fully combined. Pour the custard through a fine-mesh sieve into a large bowl and discard the vanilla beans. Pour the custard over the bread. The bread will float to the top—use a spatula to gently press down on the slices, making sure they are completely covered in custard. Place the dish in a large roasting pan or rimmed baking sheet and add enough warm water to the pan to reach about halfway up the sides of the dish. Bake the pudding for 30 minutes, then use a spatula to gently press down on the bread slices. Continue baking until the pudding is puffed and set but still jiggles in the center, about 30 more minutes. Transfer the pudding in its water bath to a rack to cool slightly. Meanwhile, in a small saucepan over low heat, warm the apricot jam with 1 tablespoon of water, stirring occasionally until liquefied, about 1 minute. Carefully remove the pudding from the water bath, then brush the surface with the warm apricot jam. Dust the top with the confectioners' sugar and serve warm. DO AHEAD: The bread and butter pudding can be prepared ahead, covered, and refrigerated up to two days. Reheat the entire dish in a water bath in a 325°F oven until the center is warm. Individual portions can be reheated in a toaster oven.
Preparation Position a rack in the middle of the oven and preheat to 325°F. Butter a 9- by 13- by 2-inch rectangular ovenproof dish. Spread the remaining butter on one side of each bread slice. Arrange the bread slices, buttered side up, in one layer on the bottom of the prepared dish. Sprinkle with the raisins and set aside. In a large saucepan, combine the milk, heavy cream, and salt. Using the blade of a small, sharp knife, scrape the seeds from the vanilla beans into the mixture; add the scraped vanilla beans. Place the pan over moderate heat and bring to a boil. Remove from the heat. In a large bowl, whisk together the eggs and sugar until pale yellow, about 1 minute. Whisk about 1 cup of the hot milk mixture slowly into the egg mixture to raise the temperature without cooking the eggs. Gradually whisk in the remaining milk mixture, whisking until fully combined. Pour the custard through a fine-mesh sieve into a large bowl and discard the vanilla beans. Pour the custard over the bread. The bread will float to the top—use a spatula to gently press down on the slices, making sure they are completely covered in custard. Place the dish in a large roasting pan or rimmed baking sheet and add enough warm water to the pan to reach about halfway up the sides of the dish. Bake the pudding for 30 minutes, then use a spatula to gently press down on the bread slices. Continue baking until the pudding is puffed and set but still jiggles in the center, about 30 more minutes. Transfer the pudding in its water bath to a rack to cool slightly. Meanwhile, in a small saucepan over low heat, warm the apricot jam with 1 tablespoon of water, stirring occasionally until liquefied, about 1 minute. Carefully remove the pudding from the water bath, then brush the surface with the warm apricot jam. Dust the top with the confectioners' sugar and serve warm. DO AHEAD: The bread and butter pudding can be prepared ahead, covered, and refrigerated up to two days. Reheat the entire dish in a water bath in a 325°F oven until the center is warm. Individual portions can be reheated in a toaster oven.