I added a little more brown sugar in mine as well, to make it a little sweeter. (sweetteaandhydrangeas.org)
The bread turned out really well, but I did have to alter the recipe by adding more brown rice flour and more cornstarch. (glutenfreecookingschool.com)
Made these this morning... the cinnamon filling was still a little runny - will try adding more brown sugar or less butter next time, but boy they were still yummy. (recipegirl.com)