01 -  Preheat oven to 350°F. Lightly grease a 9x13-inch baking dish with butter or nonstick spray. 
 02 -  Arrange the bread cubes evenly in the prepared dish. Distribute the diced apples over the surface. 
 03 -  In a large mixing bowl, whisk together eggs, whole milk, heavy cream, granulated sugar, cinnamon, nutmeg, vanilla extract, and salt until the mixture is fully blended. 
 04 -  Pour the custard mixture evenly over the bread and apples. Gently press the bread down so it absorbs the liquid. 
 05 -  In a small bowl, combine light brown sugar and ground cinnamon. Stir in the melted butter. Sprinkle this topping evenly across the casserole. 
 06 -  Allow the casserole to sit for 15 to 30 minutes, or cover and refrigerate overnight for enhanced flavor. 
 07 -  Bake for 40 to 45 minutes, until the top is golden brown and the center is set. 
 08 -  Let the casserole cool slightly. Dust with powdered sugar and serve warm with maple syrup if desired.