Preheat the oven to 350°F (175°C).

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

Add the cubed bread to the mixture and gently fold until the bread is soaked.

Transfer the mixture to a greased baking dish and spread it evenly.

Bake in the preheated oven for 45 minutes or until the top is golden brown and a knife inserted in the center comes out clean.

In a saucepan over medium heat, combine the heavy cream and sugar, stirring until the sugar dissolves.

In a separate bowl, whisk the egg yolks until smooth.

Slowly pour the warm cream mixture into the egg yolks while whisking continuously to temper the yolks.

Return the mixture to the saucepan and cook over low heat, stirring constantly, until the sauce thickens slightly.

Remove from heat and stir in the vanilla extract.