1 box butter cake mix
3/4 cup oil
8 oz. sour cream
1/4 cup brown sugar
2 cups powdered sugar
4 eggs
2 tablespoons cinnamon
4 tablespoons milk
1 tablespoon vanilla

Mix cake mix, oil, eggs and sour cream. Pour half of batter in a greased 9x13 inch pan. Mix cinnamon and sugar together: pour over batter. Cover with other half of batter. Bake at 325 for 30 to 40 minutes. While cake is hot, mix powered sugar, milk and vanilla. pour over hot cake.