Preheat your oven to 350°F (175°C). Grease a 9x13-inch baking dish.

Chop challah or brioche bread into 1-inch cubes and place them in the greased baking dish.

Whisk together 4 eggs, 2 cups of milk, 1 cup of brown sugar, 1 teaspoon of cinnamon, and a pinch of salt in a large bowl. Pour over the bread cubes.

Core, peel, and slice apples, distributing them over the bread and pressing lightly.

In a medium saucepan, combine 1 cup of granulated sugar and ½ cup of butter. Stir over medium heat until melted, then carefully add ½ cup of heavy cream.

Pour the caramel sauce over the casserole evenly.

Cover with foil and bake for 30 minutes. Then remove the foil and bake for an additional 20-25 minutes until golden brown.

Let cool for 10 minutes before serving. Top with optional toppings like nuts, whipped cream, or maple syrup.