- ¾ cup granulated sugar
- ⅛ teaspoon salt
- ⅓ cup all-purpose flour
- 2 cups milk
- 2 egg yolks
- 2 tablespoons butter
- 1 ½ teaspoons vanilla extract
- 1 vanilla bean, split with seeds removed and reserved (optional)
In a medium saucepan, combine sugar, salt, and flour. Slowly stir milk into dry mixture. Place over medium-high heat and cook, stirring continuously, until the mixture is simmering and begins to thicken. Remove from heat.
Meanwhile, use a whisk to beat egg yolks in a small bowl. Briskly whisk in a small amount of the hot milk mixture (about ½ cup), then pour the tempered egg yolk mixture into the remaining milk mixture, whisking continuously. Add the butter, vanilla and, if using, vanilla bean seeds, and whisk to combine.
Return the saucepan to the stove over low heat, then cook, stirring continuously with a wooden spoon, until the mixture becomes thick, about 5 minutes. Remove from heat and serve cooled slightly or at room temperature.