Shortcut Crumb Cake Recipe

Sometimes the shortcut recipes taste the best.  That is true in this case!! This recipe comes from my friend and when I asked her for the recipe I begged her to tell me it was from scratch and not a box.  I pleaded and I begged because I just knew.  I knew it had to start with a box mix and I was right.  This cake is outrageous. DO NOT let the box mix scare you away!!!

1 Betty Crocker Yellow Cake box mix, prepared according to box directions and also add 1 teaspoon vanilla
1 pound salted butter
4 cups flour
2 cups sugar
2 Tablespoons cinnamon
Prepare the cake as package directs and add vanilla.
Bake it in a 9×13 pan lined with nonstick foil for 15-20 minutes at 350.
Electric mix butter, flour, sugar and cinnamon to make crumbs.
Sprinkle all over the cake and return to the oven for an additional 15-20 minutes.
Let cool completely before cutting.