Preheat the oven to 350°F (175°C).

In a large mixing bowl, whisk together the eggs, heavy cream, milk, sugar, vanilla extract, cinnamon, and salt until well combined.

Add the cubed French bread to the egg mixture, gently folding to coat the bread evenly.

Pour the mixture into a greased 9x13 inch baking dish and spread it out evenly.

Cover with foil and refrigerate for at least 30 minutes or overnight.

Remove the casserole from the refrigerator and let it sit at room temperature for 10 minutes.

Bake in the preheated oven for 30-35 minutes, until the top is golden brown and the center is set.

Remove from the oven and let cool for 10 minutes.

Sprinkle the 1/2 cup of granulated sugar evenly over the top of the casserole.

Using a kitchen torch, caramelize the sugar until it forms a crispy crust.

Let it sit for a few minutes to harden before serving.