3In a large bowl, cream 1/2 cup butter and shortening till light. Add white sugar, and beat till fluffy. Beat in egg yolks. Stir together flour and baking soda, and add alternately with buttermilk into the creamed mixture; mix well after each addition. Stir in 1 teaspoon vanilla, coconut, and 1 cup pecans. Fold in stiffly beaten egg whites. Spoon into prepared pans.