1 (9-inch) unbaked pie shell
1 1/2 c. sugar
3 tbsp. flour
1/2 tsp. salt
2 c. buttermilk
3 eggs, separated
1/2 c. melted butter
2 tsp. lemon juice or vanilla

Chill pie shell. Soften butter to room temperature and butter inside of pie shell lightly; return to refrigerator until all ingredients are mixed. Heat oven to 425 degrees. Beat egg yolks lightly; add flavoring. Mix salt and sugar and flour. Stir into yolks until well blended.

Melt remaining butter and add to buttermilk. Stir into egg mixture. Beat egg whites until they peak when beater is raised. Fold into custard mixture and pour into chilled crust.

Bake at 425 degrees for 10 minutes; reduce heat to 350 degrees. Continue baking until knife inserted into center of filling comes out clean.