First, consult this dutch oven temperature chart to determine how many charcoal briquettes you'll need to heat your dutch oven to 425 degrees. Then, place the charcoal in the chimney starter and light it. If you're unsure how to use a chimney starter, refer to this instructional article.You will have about 8-10 minutes to assemble the apple cobbler before the charcoal will be ready to use. Line your dutch oven with a parchment or aluminum liner. If you don't have dutch oven liners, grease the inside of the dutch oven with butter or cooking spray to prevent the cobbler from sticking.
Open both cans of apple pie filling and pour them into the dutch oven. Spread the filling around evenly with a spoon.
Evenly pour the dry cake mix over the apple filling, making sure to cover it completely. Use a spoon to spread the dry cake mix so it is level.
Sprinkle ground cinnamon over the dry cake mix to taste, if desired.
Slowly pour the can of soda evenly over the dry cake mix. Lightly mix the soda into the cake mix with a spoon so it's fairly wet. Avoid digging down into the fruit filling.
Cut the cold butter into 1/4" squares and place them in an even pattern all around the top of the cake mix.
Place the lid on the dutch oven. Using heat-resistant gloves and long-handled tongs, place the required number of charcoal briquettes under and on top of the dutch oven in an evenly-spaced pattern.
Bake the apple cobbler for approximately 40-50 minutes. Rotate the lid and body of the dutch oven a quarter-turn each in opposite directions every 15 minutes to help with even cooking. Try to avoid opening the lid, as this will delay the cooking time. You'll be able to smell the sweet, delicious scent of the cobbler when it's almost done.
The cobbler is done when the top is golden brown and a toothpick inserted in the cake portion comes out clean. Carefully remove the lid and set it on a heat-resistant surface. Then, remove the dutch oven from the coals and set it aside to cool. Serve the apple cobbler with ice cream, if desired, and enjoy!