1 box Duncan Hines yellow cake mix
Eggs, according to box
1 c. water
1 tbsp. vanilla
Sprinkle cinnamon on cake

TOPPING:

1 stick butter
2 1/2 c. flour
2 c. sugar
Cinnamon

Mix cake ingredients; sprinkle cinnamon. Add topping; pour into rectangular roasting pan and bake 30 minutes. Remove from oven and sprinkle with powdered sugar.