1 box Duncan Hines yellow cake mix
4 eggs
1 (8 oz.) sour cream
3/4 c. oil
1 c. brown sugar
3 tsp. cinnamon
2 c. powdered sugar
4 tbsp. milk or water
1 tbsp. vanilla

Mix all ingredients together. Separately mix 1 cup brown sugar with 3 teaspoons cinnamon. Pour 1/2 the batter into a greased and floured 9 x 13 inch pan. Sprinkle 1/2 the brown sugar mix over the batter and swirl. Pour the rest of the batter over the first layer. Sprinkle the rest of the brown sugar mix over the batter and swirl. Bake at 350 degrees 35 to 40 minutes.

Mix 2 cups powdered sugar, 4 tablespoons milk or water and 1 tablespoon vanilla. Pour powdered mixture over hot cake.