Prepare the Bread: Slice your bread into thick pieces, ensuring each slice is about 1-inch thick. Arrange the slices in a 9x13 inch baking dish in an even layer.
Make the Custard: In a mixing bowl, whisk together eggs, milk, brown sugar, vanilla extract, and cinnamon until smooth and well combined.
Soak the Bread: Pour the custard mixture evenly over the bread slices. Make sure all the bread is soaked. Press gently to help the bread absorb the mixture.
Cover and Refrigerate: Cover the baking dish with aluminum foil and refrigerate overnight, allowing the bread to soak up the custard and flavors.
Preheat the Oven: The next morning, preheat your oven to 350°F (175°C).
Bake: Remove the foil and bake the French toast for 30-35 minutes until the edges are golden and the custard is set.
Serve: Let it cool slightly before drizzling with maple syrup and adding toppings like fresh fruit, whipped cream, or powdered sugar.