Preheat your oven to 350°F (175°C).
Grease a 9x13 inch baking dish with butter or cooking spray.
In a large mixing bowl, combine the eggs, milk, heavy cream, granulated sugar, vanilla extract, ground cinnamon, and salt. Whisk until well combined.
Add the cubed French bread to the egg mixture, gently folding it in until the bread is fully coated. Allow it to soak for about 10-15 minutes.
Pour the mixture into the prepared baking dish, spreading it out evenly.
Drizzle the maple syrup over the top of the casserole.
Cover the baking dish with aluminum foil and bake in the preheated oven for 30 minutes.
Remove the foil and bake for an additional 15 minutes, or until the top is golden brown and the casserole has set.
Allow to cool for a few minutes before serving. Dust with powdered sugar if desired and serve with additional maple syrup.