Spray a 9×4 inch baking dish with nonstick spray.
Arrange the bread in the dish so each slice overlaps the other.
In a large bowl, whisk together the eggs and milk.
Whisk in the brown sugar and melted butter. Then add the vanilla, cinnamon, and salt.
Pour the custard over the layered bread, making sure each slice is covered.
Cover the dish and refrigerate overnight.
Remove the dish from the fridge the next morning about 30 minutes before baking. Preheat the oven to 350° F.
Bake the French toast for 45 minutes, or until puffed, crispy, and golden.
Remove it from the oven and sprinkle with powdered sugar. Serve with fresh berries, whipped cream, and maple syrup.