In a large mixing bowl, whisk together the eggs, milk, heavy cream, granulated sugar, vanilla extract, cinnamon, and salt until well combined.
In a greased 9x13-inch baking dish, layer the torn croissant pieces evenly.
Pour the egg mixture over the croissants, ensuring all pieces are soaked. Gently press down on the croissants to submerge them in the liquid.
Cover the baking dish with plastic wrap and refrigerate overnight (or for at least 4 hours) to allow the croissants to absorb the mixture.
Preheat the oven to 350°F (175°C). Remove the plastic wrap and bake the dish for 45-50 minutes, or until the top is golden brown and the center is set.
Let the bake cool for 10 minutes before serving. Drizzle with maple syrup and dust with powdered sugar if desired. Top with fresh berries for added flavor.