The 4th at Spyglass.
Here's the fallaway back tier of #4 at The Glass:
Pinehurst National has several.....the 6th, the 8th, 14th and the 9th could all be classified in that manner.
The 6th is the one that popped in my head, and has the
biggest falloff to the back on the course. Jim, did you work
on The Course Formerly Known as PN?:
The pin is in the lower back tier in this pic:
Some others:
#15 at Inniscrone (one of the all-time great fallaway greens, IMO)
#10 at Tot Hill Farm, seen in the upper part of this shot of the 12th green:
Doak mentioned a few, but not his own 3rd at Riverfront:
#8 at Nicklaus' Hokuli'a on the Big Island (still not sure that it's pinnable back there):