Mix brown sugar and cinnamon and set aside.
Cream butter and sugar and then add eggs. Add dry ingredients alternately with sour milk; mix well.
Put half the batter in loaf pan. Sprinkle half of brown mixture over it and ad d remaining batter. Sprinkle with remaining brow sugar and cut through with a knife to give marble effect. Bake at 350� F for 45 to 60 minutes.