Preheat your oven to 350°F (175°C) and grease a 9x13 inch baking dish with butter or non-stick spray.

In a large mixing bowl, combine the cubed bread with cinnamon and sugar, tossing gently to coat each piece.

In another bowl, whisk together the eggs, milk, heavy cream, vanilla extract, and salt until well combined.

Pour the egg mixture over the bread cubes, ensuring all pieces are soaked. Use a spatula to gently press the bread down, allowing it to absorb the liquid.

Cover the dish with plastic wrap and refrigerate for at least 2 hours, or overnight for the best flavor.

When ready to bake, remove the casserole from the refrigerator and let it sit at room temperature for 30 minutes.

Uncover and bake in the preheated oven for 45-55 minutes, or until the top is golden and a toothpick inserted in the center comes out clean.

Once baked, let it cool for a few minutes before serving. Dust with powdered sugar and top with fresh berries and a drizzle of maple syrup, if desired.