- 6 tablespoons unsalted butter, room temperature
- 1 cup granulated sugar
- 2 eggs, separated
- 3 tablespoons all-purpose flour
- 1 tablespoon fresh lemon juice
- 1/2 teaspoon freshly grated nutmeg
- 1/4 teaspoon salt
- 1 cup buttermilk, room temperature
- 1 baked 9-inch deep-dish pie shell
1. Preheat oven to 350 degrees. In a medium bowl, combine butter and sugar until sugar is completely incorporated. Add egg yolks and mix well to combine. Add flour, lemon juice, nutmeg, and salt. With the mixer running, slowly add buttermilk. Mix well and set aside.
2. In another bowl, whip egg whites until they form soft peaks. Pour a small amount of the buttermilk mixture into the whites. Fold gently to combine. Gently fold egg white mixture into remaining buttermilk mixture until just combined. Pour custard into baked pie shell.
3. Bake in the middle of the oven until filling is lightly browned and barely moves when the pie is jiggled, about 45 to 50 minutes. Cool on a rack and serve warm or at room temperature.