Preheat the oven to 350F.
Spray a baking dish with nonstick cooking spray.
Break bread into 1-inch pieces and add them into an 8-inch or 9x13-inch baking pan.
In a medium bowl, combine the eggs, butter, milk, sugar, vanilla bean paste, salt, and bourbon. Beat until well mixed. Pour over bread and lightly push down with a fork until bread is covered and soaked in the egg mixture.
Bake uncovered for 45 minutes or until the custard is well puffed and set but still soft in the center.
Sprinkle with powdered sugar and enjoy with maple syrup or vanilla ice cream.