Slice the challah bread (or brioche) into thick slices, about 1-inch thick. Arrange the bread slices in a single layer in a greased 9×13-inch baking dish. You can slightly overlap the slices to fit them all in.
In a large bowl, whisk together the eggs, milk, heavy cream, granulated sugar, vanilla extract, cinnamon, and salt until smooth.
Pour the egg mixture evenly over the bread slices. Press the bread down gently with a spatula to ensure all the slices are soaked.
Cover the baking dish with plastic wrap and refrigerate overnight (or for at least 4-6 hours) to allow the bread to soak up the custard mixture.
2. Prepare the Crème Brûlée Topping:
In a small bowl, whisk together the melted butter, brown sugar, corn syrup (if using), and vanilla extract until smooth.
After the French toast has soaked overnight, pour the crème brûlée topping evenly over the bread. The brown sugar will create a crispy, caramelized top when baked.
3. Bake the French Toast:
Preheat the oven to 350°F (175°C).
Bake the French toast, uncovered, for about 35-40 minutes, or until it’s golden brown on top and set in the middle. The custard should be fully cooked, and the top should have a caramelized, crunchy texture from the brown sugar topping.
4. Serve:
Once the French toast is done, remove it from the oven and let it cool for a few minutes.
Serve warm, dusted with powdered sugar, and topped with fresh berries, maple syrup, or whipped cream.
