1. Preheat oven to 350°F. Put the bread and milk in a large bowl and mix until all of the milk is absorbed.

2. In a separate bowl, beat eggs, sugar, brown sugar, vanilla, cinnamon, and allspice together. Pour the mixture over the bread and stir to combine. Gently stir in the raisins.

3. Pour butter into the bottom of a 9x13 inch baking pan. Coat the bottom and the sides of the pan with the butter. Pour in the bread mix and bake for 40 minutes, or until the bread pudding is set and the corners are slightly browned. Let cool on a wire rack while you make the custard sauce.

4. To make the vanilla custard sauce, heat the milk and cream in a medium saucepan until boiling. Remove from heat and stir in the vanilla extract. In a medium bowl, whisk together the sugar and egg yolks until combined and a light yellow color. Temper the egg yolks by whisking in a few tablespoons of the hot cream mixture, until you've added about half of the cream mixture. Pour the egg yolk mixture into the pan with the remaining cream mixture and stir over medium heat with a wooden spoon until the custard thickens. Remove from the heat and stir in the rum extract, if using.

5. Cut the bread pudding into squares and drizzle vanilla custard sauce over each piece.

Note-the bread pudding is best served warm.