Allow butter, eggs, and sour cream to stand at room temperature for 30 minutes. Meanwhile, grease and flour a 10-inch tube pan. Set aside.
In a medium mixing bowl, combine flour and baking soda; set aside.
In a large mixer bowl, beat butter with a stand mixer on medium to high speed for 30 seconds. Gradually add sugar, beating about 10 minutes or until very light and fluffy. Add eggs, 1 at a time, beating well after each addition.
Add vanilla. Add flour mixture and sour cream alternately to egg mixture, beating on low to medium speed after each addition until just combined. Spread batter in the prepared pan.
Bake in a 325 degree F oven for 1-1/2 hours or until a wooden toothpick inserted near the center comes out clean. Cool in a pan on a wire rack for 20 minutes. Remove from pan, and cool thoroughly on a wire rack. If you like, garnish with fresh berries. Makes 16 servings.