Today I used this library for the first time and I when I was reviewing the log files it generated, I found all calling methods to be "NLog.Owin.Logging.NLogFactory+Logger.WriteCore" instead of my class methods (using ${callsite}). Digging into the the code for NLog and this library I found out that NLog goes up the stack frame and finds the calling method, but since it does not "know" anything about your library, it assumes it is the correct one. (which is wrong in this case)

The problem gets solved by adding these 2 lines to my project, but I think it should be added to the library instead, so the end-user(developer) does not have to worry about it.

LogManager.AddHiddenAssembly(typeof(NLogFactory).Assembly);
LogManager.AddHiddenAssembly(typeof(LoggerExtensions).Assembly);

Hope it helps someone.