I noticed the other day another themed cake show had started, taking the place of the Cake Wars program on Channel 33... and checking the TV guide on Wednesday night, I saw that the episode that evening had Transformers mentioned, so I figured that this might be where the transforming Optimus cake was from in those commercials a few weeks back.
I set the recorder for the midnight repeat screening, and sure enough, this was the one... and it was so much more interesting than the Cake Wars episode.
This one featured research and clips from Transformers, and ended with an actual party at the Universal Studios, with Frank Welker and Peter Cullen as featured guests.
The episode had three projects throughout the hour, but someone has posted up a youtube video of just the Transformers portions, which goes for 29 minutes. (definitely watch it if you have a chance, especially if you've never seen Peter or Frank use their Transformers voices in public before)
Doing a little research on this, the party at the end of the episode was back in February 2nd 2015, but the episode didn't air in America until May 3rd 2016.