1 box Duncan Hines Butter cake mix
1 tbsp. plus 1 tsp. vanilla, divided
1 lb. butter, softened
1 tbsp. cinnamon
4 c. flour
1 1/3 c. sugar

Preheat oven to 350 degrees.

Make cake as directed on package, adding 1 teaspoon vanilla. Bake at 350 degrees for 20 minutes. Cool 5 minutes.