Begin by slicing your brioche or challah into thick slices, about 1 to 1.5 inches. Arrange the slices in a greased 9x13 inch baking dish in a single layer.

In a large mixing bowl, whisk together 6 eggs, 2 cups of whole milk, 1 cup of heavy cream, ¾ cup of granulated sugar, 2 teaspoons of vanilla extract, and a pinch of salt until smooth.

Evenly pour the custard mixture over the bread slices, ensuring every piece is submerged. Press down gently and cover tightly with plastic wrap. Refrigerate overnight.

The next morning, preheat your oven to 350°F (175°C). Remove the plastic wrap and bake for 30-35 minutes until golden brown and set.

Remove from the oven, let cool for a few minutes, then sprinkle a thin layer of granulated sugar over the top. Use a kitchen torch to caramelize the sugar until golden.