1. Preheat oven to 325 degrees. Butter an 8 x 8 (or 2 quart) baking dish.
2. Roughly tear croissants into 1 inch pieces. Place half of the croissants pieces in the bottom of the baking dish. Sprinkle in half of the chocolate chunks. Add the remaining croissants and top with the rest of the chocolate pieces.
3. In a large bowl, combine half and half, sugar, salt, vanilla and eggs. Whisk until sugar is dissolved. Pour over croissants in baking pan.
4. Allow the croissants to soak up the liquid for for 10 minutes. Sprinkle with turbinado sugar.
5. Bake for approximately 50-55 minutes until puffed and custard is just set in the middle. Let rest at least 10 minutes before serving.