Buttermilk Pie

2 cups buttermilk
3 eggs, separated
1 cup sugar
3 Tbsp. flour
2 Tbsp. butter
juice of 1 lemon
1 tsp. baking powder
6 Tbsp. sugar
unbaked pie shell

Mix 1 cup sugar and flour, add soft butter, beaten egg yolks and lemon juice. Beat until creamy. Add buttermilk gradually, beating after each addition. Pour into unbaked pie shell. Bake at 425 degrees for 10 minutes, then reduce temperature to 350 degrees and continue baking for 20 - 25 minutes. Beat egg whites until foamy and add baking powder. Beat until stiff, gradually adding 6 Tbsp. sugar. Flavor with a few drops of lemon juice. Spread on cool pie, bake in low oven until brown.