Ingredients

1/4 cup sugar 

3 tablespoons all-purpose flour 

Pinch of salt 

1 cup low-fat buttermilk 

2 large egg yolks 

1/4 teaspoon pure vanilla extract 

1 tablespoon freshly grated lemon zest 

2 teaspoons fresh lemon juice 

Preparation

Whisk together sugar, flour, and salt; set aside. Put buttermilk and yolks in a small saucepan. Gradually whisk in sugar mixture, and cook over medium heat, whisking constantly, until thick enough to coat the back of a spoon, about 4 minutes. Stir in vanilla, zest, and lemon juice.

Pour cream into a bowl set in an ice-water bath. Let cool completely, stirring occasionally. Refrigerate in an airtight container until ready to use, up to 2 days.