I haven't tried the VWAV recipe as written or GF, but I do often get good cake results using half Bob's original GF mix (not the new cup for cup stuff) and half GF oat flour, plus a teaspoon or so of ground flax. But full-size cakes are tricky. I would definitely try a practice cake first. Also, I think that if there are lots of spices, like cinnamon and ginger, then that will disguise the bean-y flavor of the flour.
I do like this naturally GF and vegan carrot cake recipe, but I know chestnut flour is not really a pantry staple.http://webcache.googleusercontent.com/s ... clnk&gl=dk