Vanilla Crème Pâtissière (Pastry Cream)

Instructions

1. In a medium sauce pan, heat the milk over medium heat and bring it to a simmer but not quite a boil.
2. In the meantime, in a medium bowl, whisk together the egg yolks, sugar, corn starch, and salt until you have a thick, smooth mix. Whisk in the vanilla extract.
3. Stabilize the yolk mixture so it won't move while whisking (rubber-bottomed bowl, kitchen towel wrapped around the base, whatever works).
4. When the milk is properly heated and starting to bubble, remove it from the heat. While whisking constantly, slowly pour half of the milk in a thin steady stream into the yolk mixture. If you don't whisk enough, it'll get lumpy with cooked egg yolk.
5. When the eggs have been properly tempered and whisked smooth, add the egg-milk mixture to the sauce pan with the rest of the milk.
6. Over medium heat, continue whisking until the mixture starts to thicken and the foam on top goes away. It'll turn into a thick custard (thicker than pudding). Turn the heat down to low and continue to whisk and cook for another minute or two to cook out the corn starch flavor.
7. Remove the custard from heat and whisk in the butter. Do this quickly or the butter will split the custard.
8. Pour the custard into a bowl and cover the surface with plastic wrap. Don't just cover the bowl, press the plastic wrap down to the surface of the custard. This will help prevent a skin forming on top.
9. Chill the custard in the fridge until completely chilled, 4-ish hours, or overnight (hence the additional 8 hours in the total time metric), then it will be ready for use. If not chilled properly, it will be runny.