Preheat the oven to 350°F (177°C). Spray a 9 X 13-inch baking dish with nonstick cooking spray
Spread both cans of blueberry pie filling evenly in the bottom of the prepared baking dish.
Evenly spread cake mix (1 box) over the top of the filling and press down firmly. Arrange butter slices evenly over the cake mix.
Evenly sprinkle 2 cups of fresh blueberries over sliced butter.
Bake in the preheated oven for 50-60 minutes, or until the top is deep golden brown and bubbly. Let set for a few minutes and serve.
Notes
Preparation: Do not stir the ingredients, just pop it in the oven.
To Melt or Slice: This recipe does not use melted butter. By placing the cold butter evenly on top of the mix, the cake cooks perfectly every time! I found that using melted butter sometimes does not work out well.
How To Serve: Serve warm with vanilla ice cream or whipped cream.