In a saucepan, measure together the heavy cream, half and half and vanilla extract or paste. Set over medium-low heat, and cook until steaming.

In a medium-size bowl, whisk together the egg yolks and sugar.

Gradually temper the warm cream mixture into the egg base until well combined.

Return the mixture back to the pot and cook over low heat, stirring constantly, until it coats the back of a spoon. Note: This thick consistency is known as nappé.

Whisk in the whiskey, and serve warm with Pumpkin-Cinnamon Bread Pudding.