2 cups whole milk
6 large egg yolks (I’m going to use a few less next time to cut some calories)
1/2 cups sugar
1/3 cup cornstarch, sifted
1 1/2 teaspoons pure vanilla extract
3 1/2 tablespoons unsalted butter, cut into bits at room temperature
Bring the milk to a boil in a small saucepan.
Meanwhile, in a medium heavy-bottomed saucepan, whisk the egg yolks together with the sugar and cornstarch until thick and well blended. Still whisking, drizzle in about 1/4 cup of the hot milk– this will temper, or warm, the yolks so they won’t curdle. Whisking all the while, slowly pour in the remainder of the milk. Put the pan over medium heat and, whisking vigorously, constantly and thoroughly (making sure to get the edges of the pot), bring the mixture to a boil. Keep at a boil, still whisking, for 1 to 2 minutes, then remove the pan from the heat.
Whisk in the vanilla extract. Let sit for 5 minutes, then whisk in the bits of butter, stirring until they are full incorporated and the pastry cream is smooth and silky. Scrape the cream into a bowl. You can press a piece of plastic wrap against the surface of the cream to create an airtight seal and refrigerate the pastry cream until cold or, if you want to cool it quickly put the bowl into a larger bowl filled with ice cubes and cold water, and stir the pastry cream occasionally until it is thoroughly chilled, about 20 minutes.