Personally I am in the genetics camp on this one. I think if you have the potential to build the peak you will, if not, you won't that simple. I have pretty big peaks, b/c I'm lucky I think.
But as for exercises some would suggest preacher curls and/or concentration curls
But if you are fairly lean 15% or less bf, and been lifting for a decent enough amount of time, and have no bicep peak, my opinion is you probably won't ever.