Slice the Challah bread into thick slices, about an inch thick.
In a medium bowl or shallow dish, whisk together milk, eggs, cinnamon, vanilla extract, and sugar.
Dunk each bread slice into the egg mixture, turning to coat thoroughly. Allow the mixture to soak into the bread slightly.
Place the soaked bread slices onto a preheated waffle iron. Cook until each piece is golden brown. Remove and repeat with the remaining slices.
Serve the French Toast Waffles on a wire rack if desired, to prevent sogginess. Top with melted butter and drizzle with maple syrup.