Add cream cheese, egg, and granulated sugar to a medium mixing bowl.
Beat using a hand mixer (you can alternately use a standing mixer) until smooth and creamy.
Spread both cans of strawberry pie filling across the bottom of a 9×13 glass baking dish.
Drop spoonfuls of the cream cheese mixture over the strawberry filling.
Sprinkle the full bag of cake mix over the top of the other filling ingredients. A nice even layer will make it easiest to top with butter in the next step.
Slice extra THIN pats of butter and place them to cover as much of the cake mix layer as possible.
Bake until the topping is browned and the strawberry filling is bubbling around the edges.
Allow dump cake to rest for 15 minutes before scooping into it to serve.