Splendid pic Tom. I've just read your excellent TR; The path you couldn't find pretty much follows the snow line on the edge in your picture then descends the broad ridge to the Llyn. It's possible that you couldn't find it cos it was obscured by the snow.It soon picks up a good farm track (Maybe the one you drove up) but before the road a path crosses a bridge to return to the tea room. There's also another path that descends steeply to the other side of the Llyn, but IIRC it's very wet underfoot on that side..It's a superb little walk. Try it again on a summer's day and do the loop. It probably won't be any busier either...
My four year old Freddie, enjoying the snow this morning