1 box yellow cake mix (follow directions)
1 c. sour cream
1 c. brown sugar
2 tsp. cinnamon

ICING:

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

Follow directions on cake mix and add the 1 cup sour cream. Set aside. Mix the 1 cup brown sugar and 2 teaspoons cinnamon together. Spread 1/2 cake batter in 9 x 13 inch pan and spread 1/2 sugar mixture over this. Repeat layer. Swirl mixture with a knife.

Bake at 325 degrees for about 40 minutes. Pour icing on while cake is hot.