1 Box Yellow Cake Mix (plus ingredients on back of box)
(Note: I have also used other flavors of cakes, for example, pink lemonade)
2 Sticks cold salted butter, cut into large pieces
2 1/4 Cups flour
1 1/2 Tablespoons cinnamon
1 ¾ Cups brown sugar
1 1/2 Tablespoons vanilla
Powdered sugar (for dusting)
PREHEAT oven to 350.
PREPARE cake mix in large bowl according to directions on box.
Spray 9X13 pan with non-stick spray.
Pour batter into pan. Bake at 350 for 15-20 minutes or until center is just barely set.
WHILE cakes are baking, prepare crumb topping: In large bowl, whisk together flour, cinnamon, and sugar.
Add vanilla and stir to distribute.
Cut butter in using two knives, and at some point switch over and use your hands. (I wear gloves, otherwise it gets under your fingernails).
Keep loosely mixing with your hand until mixture softens.
You want a soft consistency where the butter is worked in, not the kind of little pieces you get when you use a food processor making a pie crust where you want tiny pieces of butter covered with flour.
You can actually lump it all together and then break off pieces as indicated below.
IMMEDIATELY after cake is removed from oven, lightly toss or break crumb topping (if you have it in a clump) into marble size pieces with fingers, sprinkling over top. Put back in oven and bake an additional 10-15 minutes.
Let cool fully then dust with powdered sugar, using a sieve.