Creating the Crème Brûlée French Toast is a straightforward process if you follow these steps:

1. Prepare the Bread: Slice the brioche or challah into thick slices (about 1 inch).
2. Prepare the Baking Dish: Grease a 9×13-inch baking dish with butter.
3. Make the Custard: In a large mixing bowl, whisk together the eggs, heavy cream, whole milk, sugar, vanilla extract, and salt until fully combined.
4. Combine Bread and Custard: Arrange the slices of bread in the greased baking dish. Pour the custard mixture over the bread, ensuring each piece is well coated. Press down gently to submerge the bread into the mixture.
5. Chill: Cover the dish with plastic wrap and refrigerate for at least 1 hour, or overnight for best results.
6. Preheat the Oven: Preheat your oven to 350°F (175°C).
7. Bake: Remove the cover and bake the French toast in the preheated oven for 35-45 minutes, or until the custard is set and the top is golden and slightly puffed.
8. Cool: Allow the dish to cool slightly before proceeding to the next step.
9. Caramelize the Sugar: Sprinkle the sugar evenly over the top of the French toast. Use a kitchen torch to caramelize the sugar until golden brown and crispy. If you don’t have a torch, place the French toast under the broiler for a few minutes—watch carefully!
10. Serve: Let the caramelized sugar cool and harden before slicing into portions.