Slice bread into small chunks. Transfer them to a non-stick pan, set over low heat and toast bread until it’s golden and dried out. (Skip this step if you’re using stale bread.) Transfer bread to baking dish and drizzle butter over the bread. Sprinkle with chocolate chips.
In a medium bowl, whisk together milk, cream, sugar, salt and eggs. Then stir in orange juice and zest. Pour mixture over the bread and let stand for 30 minutes (or overnight - in the fridge). Using a spoon, push down any piece of bread that is poking out of the liquid.
Preheat oven to 350°F (175°C) with a rack placed in the center of the oven.
Bake bread pudding for 45 minutes or until it’s puffy, light brown in color and the custard has set. (Check bread pudding every 15 minutes as it bakes. If you notice the bread is getting too dark too soon, loosely cover the top with aluminium foil and keep baking.)
Remove bread pudding from oven, sprinkle with powdered sugar, slice and serve. I offer whipped cream on the side, for anyone that likes it.