1 stick butter, soft
1 1/2 c. sugar
1 tbsp. vanilla
1 tbsp. flour
3 egg yolks
1 c. buttermilk
3 egg whites (beaten stiff)

Mix first 5 ingredients. Add buttermilk. Fold in beaten egg whites. Fill one 9 in. unbaked pie crust and bake at 325°F for one hour.