Platinum Girl Scout Cookies, and Platinum OG, are two very real strains, and not just fancy names made up by dispensaries. I can't say exactly what the parents were crossed with, as it seems to be a well guarded secret, but both are considered by many to be better than the originals.
The main difference between Girl Scout Cookies, and Platinum Girl Scout Cookies, is the yield. Platinum yields better than GSC, but then again, GSC is a notoriously low yielder to begin with.
Here's a Platinum Girl Scout Cookies that I grew a couple of months ago, very potent, and very beautiful.
Platinum Girl Scout Cookies