Preheat 25 briquettes (for 12" oven)

Line dutch oven with foil, parchment paper or butter

Pour blueberries and pie filling into lined dutch oven, then mix together

In a separate bowl mix together cake mix, butter pieces and Sprite. Batter thickness can be to your taste, anywhere from thick biscuit consistency to a thinner cake batter. I prefer to keep it thin enough to pour and spread.

Spoon or pour batter over the top of the blueberries, then sprinkle on sugar liberally.

Place oven over 8 preheated briquettes, then place 17 briquettes on the oven lid. This will generate a theoretical 350° inside the oven.

There are charts available online if your oven is a different diameter, which will tell you how many briquettes you need on the top and bottom of your oven to hit your desired temp.

Lift and turn oven every 10 minutes to prevent hot spots on the bottom.

After 1 turn, preheat the 2nd 25 briquettes.

After the 3rd turn (first 30 minutes of baking), add the now preheated briquettes in the same ratio. Don't bother removing the old briquettes.

After 6 total turns, top should be golden brown, and visible fruit filling should be bubbling. If not, keep turning until it is. Test batter for doneness and serve.