In a medium saucepan add the milk, heavy cream, granulated sugar, and butter. Set the heat to medium and using a whisk stir until the butter melts (about 3 minutes).
Once the butter has melted, in a small bowl combine the water and cornstarch to create a slurry. Make sure the cornstarch and water is fully combined then add it to the cream mixture.
Stir to fully combine.
Using your whisk, continue to stir the mixture until it starts to thicken and bubble (about 3 minutes).
Once it starts to thicken and bubble, add the vanilla extract and salt.
Stir to fully combine the vanilla and salt into the mixture.
Allow the mixture to continue to thicken. You’ll want to have a consistency of runny pudding for about 2 more minutes. Once you get to that consistency, remove from heat and allow to cool for a few minutes before topping the sauce over your bread pudding.
