In a large bowl, cream butter and sugar until light and fluffy. Add eggs, one at a time, beating well after each addition. Combine flour and baking soda; add alternately with buttermilk and beat well. Stir in vanilla.

Pour into a greased and floured 10-in. fluted tube pan. Bake at 325° for 70 minutes or until a toothpick inserted near the center comes out clean. Cool in pan for 15 minutes before removing to a wire rack to cool completely. Dust with confectioners' sugar if desired. Yield: 16-20 servings.