MIX flour and baking soda. Beat butter and sugar in large bowl with electric mixer on medium speed until light and fluffy. Add eggs, 1 at a time, beating well after each addition.
ADD flour mixture to sugar mixture, alternately in thirds with sour cream, beating well after each addition. Add vanilla; mix well. Pour into greased 10-inch tube or 12-cup fluted tube pan.
BAKE at 325°F for 1 hour 20 minutes or until toothpick inserted near center comes out clean. Cool in pan on wire rack 10 minutes. Remove from pan. Cool completely.