Put the rhubarb, brown sugar and water in a sauce pan or small dutch and simmer until the rhubarb starts to thicken. Add the cinnamon red hots and stir until they’re dissolved. Let the rhubarb mixture cool a few minutes while you mix up your cake mix. Next set your 12 inch dutch over 4-6 coals and melt your margarine. Make sure the melted margarine completely covers the bottom of the dutch. Spoon the rhubarb into the dutch and spread evenly. Pour the cake mix over the rhubarb. Bake with 20-25 coals on top about 40 minutes