They are on the menu at the Lunching Pad (under Astro Orbiters, by PeopleMover). That is the only place I have ever bought them over the years. Looking forward to enjoying one next month.
Below is what was written by the person that found them. It is on the thread on the restaurants board titled "food items you always seek out"
"We found them at the stand outside of the GMR in December (our tour guide didn't even know they'd brought them back). Hopefully, they're still there in June!"