I like Glenns idea of the fake log rake / barge / verge board IF you have allowed enough roofing to over hang to protect that thick a rake board. If not I'd go for a normal rake board, 3/4" thick, as it does appear that you have enough roofing to cover that thickness board. I think hard to tell exacting from the photo.
But you don't want a board or 1/2 log sticking out so water can run in , wick in between the rafter and trim piece , that invites ROT.
Again it's that whole thing of keeping the water out / thinking like rain deal.
It also appears you have your roof sheathing running past the last rafter / rake / barge rafter about 2 " or more. I cover that "end grain" of the ply either with what called a shingle mold , ( which can be a 1x2 , or a molded piece of trim , different areas do different things ) or by simply holding the rake board up the thickness of the sheathing so the sheathing is hidden by the rake board.