Break up bread in half pieces; place in crockpot if you are using a soft bread, keep aside if you are using a hardier or more stale bread. Combine eggs, millk, cinnamon, light brown sugar, and vanilla. Pour over soft bread. If you are using a hardier or more stale bread, dunk pieces individually and layer them. Set crockpot to lowest setting. Cook for at least 6 hours. Remove the lid in the morning; about 15 minutes before serving and it will brown and toast. Spoon out and serve with your choice of breakfast toppings.