Preheat the oven to 350 degrees F.
Melt butter in a 12-inch Dutch oven over low heat. Mix sugar, flour, baking powder, and salt in a medium bowl. Stir in milk and water gradually, mixing just until moistened. Pour into Dutch oven. Pour fruit over top. Cover with a lid, place coals on top, and cook for 30 to 40 minutes, or until batter is lightly browned on top. Check to make sure that batter is fully cooked through. Remove from heat, let cool slightly, and then serve warm.