1 box yellow cake mix
4 eggs
3/4 c. oil
8 oz. sour cream
1 c. brown sugar
1 tbsp. cinnamon

Frosting:

2 c. powdered sugar
4 tbsp. milk
4 tsp. vanilla

Combine cake mix, eggs, oil and sour cream. Pour 1/2 batter into well-greased 9 x 13-inch pan. Mix together brown sugar and cinnamon. Sprinkle half cinnamon-sugar mixture over first layer of batter. Pour remaining batter over cinnamon-covered batter. Sprinkle rest of sugar-cinnamon mix on top.

Bake at 325°F for 40 minutes. Frost with sugar, milk and vanilla, mixed well.