Butter 13x9-inch baking dish. Place croissants in large bowl; pour 8 tablespoons melted butter over croissants and toss to coat. Add chocolate chips and toss to combine. Transfer mixture to the prepared dish.
Whisk half & half, 1 cup sugar, eggs, egg yolks, vanilla extract, and salt in large bowl to blend. Pour over croissant cubes in dish. Let stand 30 minutes, occasionally pressing bread cubes into liquid. Sprinkle the top with brown sugar. Bake bread pudding until golden brown, and set in center, about 1 hour. Serve warm with glaze drizzled on top.
To make the glaze, combine everything together and whisk until smooth.
Notes
This recipe is very forgiving. Use whatever milk you have on hand if you don't have half and half. You can also use raisins for some or all of the chocolate - or add it to the chocolate!