Start by preparing your pie crust into the bottom of an appropriately sized pie pan, bake according to instructions on pie crust box.
Pour in two cans of cherry pie filling.
Top with half box of vanilla cake mix evenly coating the top of the pie to about 1/2-1/4 inch thick.
Thinly slice butter and distribute evenly across whole pie. Be sure that it's spread evenly, as this is what creates the "crumble" on top.
Bake in the oven for about 30 minutes on 350 or until golden brown and all cake mix has melted in with the butter.
Enjoy warm or cold...it's delicious no matter how you eat it. Can enjoy with other fillings too in the same way.