1 stick (1/2 cup) butter
1 can blueberry pie filling
Preheat oven to 350. Cut the butter into small cubes. In a large bowl, cut the butter cubes and cake mix together with a pastry cutter, or two forks, until crumbly. Set aside 1 cup of the mixture. Line a 13×9″ baking dish with parchment paper or cooking spray, dump in the remaining cake mix/butter mixture into the bottom of the baking dish at press it down with your fingers to pack it together over the bottom baking dish and slightly up the sides. Drop spoonfuls of the pie filling over the packed crust mixture, and carefully spread it with the back of a spoon as evenly as possible. Sprinkle the reserved cup of the crust mixture over the pie filling and bake for 35-45 minutes. Cool Completely, cut into 12 squares, and serve.