Mix remaining flour, baking powder and baking soda. Beat 1/2 cup softened butter and granulated sugar in large bowl with mixer until light and fluffy. Blend in eggs and vanilla. Add flour mixture alternately with sour cream, beating until blended after each addition. Stir in apples. Pour into greased and floured 10-inch tube pan or 12-cup fluted tube pan. Sprinkle with nut mixture.