Preheat your oven to 350°F (175°C).
Grease the 9x13 inch baking dish lightly with butter or cooking spray.
Cut the bread into cubes (about 1-inch in size) and place them evenly in the prepared baking dish.
In a mixing bowl, whisk together the eggs, milk, heavy cream, sugar, vanilla extract, cinnamon, and salt until well combined.
Pour the egg mixture evenly over the bread cubes, ensuring all pieces are soaked. Press down gently to submerge the bread.
Cover the baking dish with plastic wrap and refrigerate for at least 30 minutes, preferably overnight, to allow the bread to soak up the egg mixture.
Once ready to bake, remove the plastic wrap and bake in the preheated oven for 45 minutes or until the top is golden brown and a knife inserted in the center comes out clean.
Let the casserole cool for about 5-10 minutes before slicing it into squares and serving.
Drizzle with maple syrup and dust with powdered sugar if desired.
