Sour Cream Coffee Cake and Icing

I misplaced this recipe for years and only found it recently.

Sour Cream Coffee Cake and Icing

Cake:  1 box (about 18.25 oz.) Duncan Hines yellow cake mix*

           1/3 c sugar

           1/3 c water

           1/3 c vegetable oil

           4 eggs

           1 c (8 oz) sour cream

           1/2 c butter, melted

           3 tbsp instant coffee crystals

Preheat oven to 350 degrees.  Combine all ingredients except for coffee crystals.  Fold in coffee crystals.  Pour into 9 x 13" pan and bake 35-40 minutes.  Leave cake in pan.  Cool completely before icing cake.

Icing:  5 tbsp flour

           1 tbsp instant coffee crystals

           1 c milk

           1/2 c butter

           1 c sugar

           1 tsp vanilla

In a medium saucepan, combine flour, instant coffee crystals and milk.  Add butter, sugar, and anilla to flour mixture and cook until thick, stirring often.  Cool completely before icing cake.

*If using a new (2013 or later) cake mix (about 15 oz.), add 6 tbsp flour to cake mix before proceeding with recipe.