AI want to make a hunting themed cake forum boyfriends birthday. I am wondering how to do a textured tree bark. Maybe with some brown sugar or crushed Oreos. Any ideas?

I did a tree stump cake with birds on it, melted chocolate in a pan in the oven, let it cool then broke it into pieces, stuck it right on the butter cream...I loved the way it 

I love the chocolate tree bark.  There are also impression mats out there that have the tree bark design.

This may be more rustic/simplistic than you are looking for, but I found dragging the tines of a fork through chocolate ganache makes very easy yet realistic bark.  Add a few circular motions for knot holes and you're set.  Took me about 5 minutes Christmas morning (all the time I had!) to do this:

http://cakecentral.com/g/i/2880619/yule-log/u/878806/flat/1/

Wish I had seen this at the beginning of the week, I made a cake with a standing bear, but I was never quite happy with the tree stump or the bear.  The birthday girl loved it.  Sigh..