Prep the pan and oven: Heat oven to 350°F (175°C).
Grease a 9x13-inch baking dish with butter.
Cube the bread: Cut bread into 1-inch cubes. If it’s fresh, spread cubes on a sheet pan and toast 8–10 minutes to dry them slightly.
Prep the apples: Peel (optional), core, and chop apples into small bite-size pieces. Aim for even dice so they bake uniformly.
Make the custard: In a large bowl, whisk eggs, milk, cream, granulated sugar, 1/3 cup brown sugar, cinnamon, vanilla, and salt until smooth.
Combine: Add bread cubes and apples to the bowl.
Stir to coat thoroughly. Let sit 10–15 minutes so the bread absorbs the custard. Fold in raisins or nuts if using.
Assemble: Pour mixture into the baking dish.
Drizzle melted butter over the top. Sprinkle the remaining 2 tablespoons brown sugar evenly for a caramelized crust.
Bake: Bake 40–50 minutes, until the center is set and a knife inserted comes out mostly clean. The top should be golden with crisp edges.
Rest and serve: Let cool 10 minutes.
Serve warm as is, or add powdered sugar, caramel sauce, or a scoop of ice cream.