2 sticks butter
3 c. sugar
6 eggs, separated
1 tsp. vanilla
1 c. sour cream
1/4 tsp. baking soda
1/4 tsp. salt
3 c. flour

Cream butter and sugar, add one egg yolk at a time. Add sour cream alternately with flour (sift flour with salt and soda in it and measure carefully). Beat egg whites in a separate bowl and fold in last. Add vanilla. Bake at 300 degrees for 1 1/2 hours.