I've discovered lots of things which work, as I won't give up all sugar or treats. My daughter uses the Kinnikinnick chocolate cake mix with coconut oil instead of butter, and used coffee instead of the milk/water it calls for. It's awesome! You need to make sure the oil is at room temp for it to mix well.
There are good options for fiber, too, such as quinoa and teff and of course, flax seeds. More and more protein bars and even cookies are GF. I'm a fan of Pamela's mini chocolate chip cookies and I just had Dr. Lucy's chocolate chip cookies. They are really crunchy!
Good luck, and come share your discoveries. You may find things we don't!
Kathy/Kate, depending on which team
"It is only with the heart that one sees rightly; what is essential is invisible to the eye."
Antoine de Saint Exupery: The Little Prince
"To the world you may be one person, but to one person you may be the world."