The day before combine 1 lb butter, 2 C brown sugar and 4 T cinnamon well then shape into a block that can be frozen and grated then freeze it (if you cant do the day before, freeze for at least two hours)
Place 2 T milled chia and 1/2 C warm water in a cup, let soak 2 minutes
Meanwhile, dissolve yeast and 1 T sugar in warm milk, let sit to proof
Using a stand mixer with the paddle attachment, combine all flours, starches, xanthan gum, baking powder, salt, sugar and gelatin
In another bowl, mix the soaked milled chia and yeast mixture together with eggs, coconut oil, butter and apple cider vinegar then slowly add that mixture to the flour mixture in stand and combine until well blended
Roll the dough out to a rectangle shape about 18x24 inches on plastic wrap that is heavily sprinkled with white rice flour and grate the frozen butter brown sugar mixture onto the dough evenly, it will be a large pile
Starting at one end, roll the dough into a cylinder and as you go, tuck the edges in with your hands so it stays even (this will keep from dough hanging out on the ends and gives you an even roll)
Slice into 10 equally sized pieces and round them out into nice circles with your hands
Place 6 in a greased 9x13 pan and 4 in a 8x8 pan and let rise for 1 hour on bread proof or 100 degrees
Once risen, bake at 350 degrees for 22-24 minutes
Meanwhile, prepare the frosting by whipping the butter, softened cream cheese, vanilla and powdered sugar together until smooth and creamy
Remove from oven and frost what you plan to eat immediately