if you have msr brand stoves, throw the brownie mix in a fryin pan and put a lid on it.......  then use the heat screen to keep the pan off the stove and its direct heat, setting the pan on top of it while it is circled around your stove.......  

sometimes it's tricky, especially if you have a heavy fryin pan, but if your pan is wide enough, it will sit 4 or 5 in. off the flame and you will get a much better and more even cook than right on the flame........  this also works for pizza dough or any other breads/ baked goods......  you might need to flip them after some time, so make sure they aren't runny......  oh yeah, and if it isn't a non-stick pan, make sure you use a lil pam or butter or sumpin, or it will be a disaster......