This is the mother of all sweetness! I found this recipe at All Recipes - it is very close to what I was given and it was part of the wonderful bread pudding I made this weekend.
Stay with this while you're making it - stir, stir, stir. Don't let it boil or it will break the sauce. Simmer good. Boil bad.
1 cup heavy cream
2 teaspoons vanilla extract
4 egg yolks
1/3 cup white sugar
In a small, heavy saucepan, heat cream and vanilla until bubbles form at edges.
While cream is heating, whisk together egg yolks and sugar until smooth. Slowly pour 1/2 cup of hot milk mixture into egg yolks, whisking constantly. Gradually add egg yolk mixture back to remaining milk mixture, whisking constantly. Continue to cook, stirring constantly, until the mixture coats the back of a spoon.
This will be the mother of all desert parts in the future!