Preheat & Prep: Preheat the oven to 350 degrees F and grease a 9x13 baking dish.

Plump the Raisins: Add the raisins, 1 cup water, 2 tablespoons butter, and 1 teaspoon cinnamon to a small saucepan over medium-high heat. Bring the mixture to a boil and continue cooking until the raisins plump up and about double in size, then remove from heat.

Mix the Custard: In a large bowl, whisk together the eggs, whole milk, heavy cream, 1 tablespoon vanilla extract, white sugar, and 1 tablespoon cinnamon. Add the warm raisin mixture to the bowl, including the remaining water from the saucepan.

Soak the Bread: Stir the cubed challah bread into the egg mixture until fully combined. Let the liquid absorb into the bread for 10 minutes.

Prepare for Baking: After 10 minutes, transfer the soaked bread mixture to the prepared baking dish and cover tightly with aluminum foil.

Bake: Bake in the preheated oven for 50 minutes. Then, remove the foil and bake for an additional 10-15 minutes until the top is golden brown and crispy.

Make the Glaze: For the glaze, whisk together the powdered sugar, 1 teaspoon vanilla, 2 tablespoons milk, and ½ teaspoon cinnamon until smooth.

Finish & Serve: Pour the sweet glaze evenly over the warm bread pudding just before serving. Enjoy!