butter and sugar. Beat in eggs and vanilla. Combine flour, baking soda and salt. Stir into the creamed mixture alternately with buttermilk. Fold in apple and nuts. Pour into a greased 9 x 5 x 3 loaf pan. For topping, combine the first four ingredients; cut in butter until crumbly. Sprinkle over batter. Bake at 350 for 55 - 60 minutes or until bread tests done. Cool in pan for 10 minutes before removing to wire rack.