Preheat oven to 350 F. Lightly grease a 9x13-inch glass baking dish with non-stick cooking spray.
Spread both cans of the fruit filling into the base of the baking dish and spread into an even layer.
Add 12 spoonful dollops of the whipped cream cheese onto the blackberry pie filling, evenly spread out.
In a small mixing bowl, cut the butter into the dry cake mix until crumbles form.
Sprinkle the crumbled cake mix-butter combo over the fruit filling and cream cheese in the baking dish. Spread evenly and flatten as best you can.
Bake in the preheated oven for 45 to 50 minutes, or until the top is golden brown. Let cool slightly.
Serve Blackberry Dump Cream Cheese Cake warm, at room temp, or chilled - best with vanilla bean ice cream or whipped cream topping. Enjoy!