1 box Duncan Hines butter recipe cake mix

CRUMBS:

2 c. flour
1/2 lb. butter, softened
1/2 c. sugar
1/4 tsp. salt
1 tbsp. cinnamon

Make cake according to box. Pour into 9 x 12 inch pan. Bake 20 minutes. Mix crumb ingredients with fork to form crumbs. Sprinkle over hot cake and return to oven for 15 minutes.