Grease a 9x13-inch baking dish with butter.
Spread the cubed bread evenly in the dish. Sprinkle raisins/chocolate chips (if using).
In a bowl, whisk eggs, milk, sugars, vanilla, cinnamon, nutmeg, and salt until smooth.
Pour the custard over the bread, pressing lightly to soak all pieces. Let sit for 10-15 minutes.
Bake for 40-45 minutes until golden and set (no liquid when tested with a knife).
In a saucepan, heat cream, brown sugar, and butter until melted. Simmer for 3-4 minutes, then stir in vanilla. Drizzle over warm pudding.
Enjoy warm with vanilla ice cream or whipped cream!