I'm back, Connie. here's the recipe, adapted from Jacques' version:
2 T cornstarch
scant 1/2 cup sugar
4 large egg yolks
generous 2 cups milk
1 vanilla bean
1 T unsalted butter, optional
Sift cornstarch and half the sugar together, add egg yolks, whisk until thick and well blended.
heat milk and remaining sugar over medium high heat in a large saucepan (mix will gain volume while cooking, so a large pan is needed to prevent spillage while whisking. Cut vanilla bean in half and scrape out seeds - add seeds and skin to heating milk. Bring to boil.
Temper egg mix by pouring about half the milk into egg mix. Whisk to prevent eggs from scrambling. then pour tempered mixture back into saucepan with the rest of the milk. Keep whisking.
As the temp increases the mixture will thicken - it will get very thick just before it boils. Keep whisking once it boils and cook for another couple of minutes to cook out the starch flavor.
Take saucepan off the heat and strain pastry cream to remove any cooked egg and vanilla bean bits. Add butter now if you want to, stirring until it is incorporated.
Pour pastry cream into clean airtight container and place plastic wrap right on the surface to prevent skin forming. Cool at room temp, then refrigerate for up to 3 days. Add flavorings at any point in the process, but use small amounts and taste test as you go so it doesn't get too runny. Non-alcoholic-based flavorings should be added at the beginning.