Use 12" DO
Prepare presorted bag of briquettes.
Stir together the cookie mix, eggs and butter in bowl.
Line DO with parchment.
Press half the batter into the bottom of the lined DO.
Sprinkle half the bag of white chocolate chips.
Press the other half of cookie batter, and sprinkle the remaining chips. Cover with the lid.
Put 1/3 of the coals on the fire pan, put the DO on the coals, and the remaining coals on the lid.
The cookie bakes in about 45 minutes or up to an hour. Mostly, if it's aromatic, it's done.