Line oven with foil (12”).
Heat brown sugar, cocoa and water in oven.
Mix in Devil’s Food cake mix and put mini marshmallows on top.
Bake with 12 coals under and 8 coals on top for 40-50 minutes, cook slowly.
With 10 minutes left, sprinkle with chocolate chips.
Remove from oven, let cool.
Top with cool whip and sprinkle with more chocolate chips.