1 box yellow cake mix
3/4 c. oil
4 eggs
1 (8 oz.) sour cream

Mix together. Pour half into greased 9 x 13 inch pan. Mix 1 cup brown sugar and 3 teaspoons cinnamon. Sprinkle half over batter. Pour remaining batter. Sprinkle remaining sugar mixture. Take knife and swirl batter. Bake at 350 degrees for 35-40 minutes.

ICING:

2 c. powdered sugar
4 tbsp. milk or more to make thinner
1 tsp. vanilla

Drizzle over hot cake.