Thanks for all the suggestions. I am assuming the worst but hoping for the best. The more I think about it, the more I think it may be an intake or valve cover gasket leak. Any other options are not so good...
I have checked the calibration on my torque wrenches tonight and I plan on tightening everything up in the morning. One way or another, I will figure out where the
oil is coming from tomorrow. The thing that has thrown me off is that the leak only occurs when I shut the engine down.
I will let you all know what I find out this weekend.