Black Walnut Sour Cream Cake
["1 c. softened butter", "3 c. sugar", "6 eggs", "1 c. sour cream", "1/4 tsp. soda", "3 c. cake flour", "1 tsp. vanilla", "1 c. chopped black walnuts"]
["Preheat oven to 300\u00b0.", "Separate egg whites.", "Beat whites with 1 cup sugar, until stiff.", "Set aside.", "In large bowl mix butter and remaining sugar.", "Beat until fluffy.", "Add egg yolks; mix until blended.", "Add soda to sour cream and add to sugar mixture, alternating with sifted flour.", "Fold in vanilla, walnuts and beaten egg whites.", "Pour into greased and floured tube pan.", "Bake 1 1/2 hours.", "Turn oven off.", "Leave cake 1 minute more.", "Take out. Leave upright 15 minutes.", "Cool 1 hour."]
["butter", "sugar", "eggs", "sour cream", "soda", "cake flour", "vanilla", "black walnuts"]