Preheat oven to 350 degrees. Grease a bundt pan very well. Sprinkle half of cinnamon and sugar mixture over the entire bundt pan until coated. Set pan aside. In a medium-size mixing bowl, cream together butter and sugar. Add eggs and sour cream. Mix well. Add flour one cup at a time. Stir in vanilla and baking soda until evenly mixed. Pour half of the batter into the coated pan. Sprinkle remaining cinnamon sugar mixture over batter. You can also sprinkle some pecans or walnuts on, if you would like. Spoon remaining batter into pan. Bake 45 minutes. Turn cake out of pan onto a serving plate immediately. Cake can be iced with a glaze or with a confectioners frosting.
