1. Preheat oven to 375°.
2. Combine sugar and cinnamon in a medium bowl; stir well. Add egg, egg white, vanilla, and salt; stir well. Gradually stir in milk. Add the bread cubes; stir well and let stand 5 minutes. Transfer mixture to 4 (8-ounce) custard cups or small ramekins coated with cooking spray.
3. Place cups on a baking sheet; bake for 35 minutes or until puffed. Transfer cups to small dessert plates; let stand at least 10 minutes (puddings will settle upon cooling). Dust puddings with powdered sugar; serve.