• Preheat oven to 150 degrees C and place a rack in the center. Lightly grease with butter or spray a 9 x 13 x 2 inch (23 x 33 x 5 cm) heat-proof baking dish.
• Place the baking dish into a larger roasting pan that has enough room around its sides to fill with water.
• Place the bread cubes and raisins (if using) in the baking dish.
• In an electric mixer (or with a hand mixer), beat the eggs and sugar on high speed until thick and lemon colored (about 4-5 minutes). Beat in the vanilla extract and ground cinnamon. Then beat in the melted and cooled butter and combination of milk & cream.
• Carefully pour (or ladle) the prepared custard over the bread cubes until completely covered. Press down the bread cubes so they are covered with the custard.
• Prepare a water bath. (A water bath is used to provide temperature protection for the egg custard.) Carefully pour in enough hot water so that the water is halfway up the sides of the 9 x 13 inch baking pan. Bake for about 1 hour or until a toothpick inserted in the center comes out clean. Another way to judge whether the pudding is fully baked, is to gently press down on the center of the pudding. If any custard comes up to the top, the pudding needs to be baked a little longer.
• Remove the bread pudding from the water bath and cool slightly before serving.
• Can be served warm or cold with a dusting of confectioners' sugar and a dollop of softly whipped cream or vanilla ice cream.

For the Sauce

• Gather your ingredients and grab a medium saucepan. Combine the milk, cream, sugar, and butter. Turn your stovetop heat to medium.
• As the mixture heats, keep an eye on it and stir occasionally. We want the butter and sugar to melt completely, and the mixture to start steaming – a sign it's getting happy and ready for the next step.
• While the milk mixture works its magic, let's create our thickening agent. In a separate bowl, whisk together the cornstarch with ¼ cup of water. If you're feeling adventurous, swap the water for bourbon or rum for a boozy twist!
• Once the milk mixture is steaming, slowly whisk in the cornstarch mixture. Here comes the important part: keep stirring constantly! This ensures the sauce thickens evenly and smoothly. You'll know it's ready when the sauce reaches a nice, nappe consistency – that means when you spoon some sauce, it coats the back of the spoon without being runny.
• Remove the pan from the heat and stir in the vanilla extract. If you choose to add a touch of rum, now's the time!
• Pour some of this delightful sauce over your warm bread pudding, and don't forget to serve the rest on the side for extra drizzling fun!