Linda-
Make sure you are not baking the regular recipe to long- they are muffin-like so it should be springy to the touch. I keep mine in individual baggies in the fridge- I like to micorwave them for a few seconds to warm them up for breakfast.
If you add baking cocoa you will need more surgar and probably more mosture (maybe even a little fat)- I never tried making them chocolate flavored as I use my chololate muffin recipe (also fat free) for my chocolate fix- I never have liked using much fiber in low fat/fat free recipes that use baking cocoa as it jsut doesn't taste good to me.
Please try the recipe again, very carefully. Make sure you have wheat bran and not wheat germ- they look a lot alike but the results from baking would be very different as would the calories/fat. Make sure you mix by hand- literally if you have to- if you over work the dough it affects the taste of any bakegoods. I don' t know what else to suggest
I have made hundreds of them as has my mom as have many others here.
Christine