Orange Sour Cream Cake
["2 c. plain flour", "1 tsp. baking powder", "1 tsp. baking soda", "1/4 tsp. salt", "3 egg whites, room temperature", "1 c. margarine", "1 c. sugar", "3 egg yolks, room temperature", "1 Tbsp. grated orange peel", "1/2 c. chopped walnuts", "1 c. sour cream", "2/3 c. fresh orange juice", "1/2 c. sugar"]
["Heat oven to 325\u00b0.", "Grease and flour Bundt pan.", "Mix flour, baking powder, baking soda and salt.", "Beat egg whites until stiff. Beat margarine and sugar in another bowl until fluffy.", "Beat in egg yolks one at a time.", "Stir in orange peel and walnuts.", "Add 1/3 of the dry ingredients and 1/2 of the sour cream and beat. Add 1/2 the dry ingredients and remaining sour cream and beat well.", "Add remaining dry ingredients.", "Fold in egg whites.", "Bake one hour."]
["flour", "baking powder", "baking soda", "salt", "egg whites", "margarine", "sugar", "egg yolks", "walnuts", "sour cream", "orange juice", "sugar"]