I've not seen this cultivar before, but I really want one now!
Since 'Pink Zazzle' was only introduced this year, information about it from gardeners may be sparse at the moment. Since the plant is rather small and there's not a lot to cut from, I wonder if layering would be a safer choice? Opinions?
Also, I don't know what species were used in this cross, but Gomphrena haageana and Gomphrena 'Fireworks' can behave like short-lived perennials where winters are mild. They form an enlarged base that looks kind of like a tuber but I'm guessing is really a caudex ....but I'm not really sure.
As far as seeds, it could be sterile since it seems to be an interspecific cross. If it does set seeds, the resulting plant will likely be variable, as mentioned by Patti and Rick. If you want to collect seeds, wait until the flower turns tans in color and collect the flower head before it shatters. The seeds, if any, will be hidden at the base of the papery coverings. It can be difficult to tell the chaff and the papery-covered seed apart. Here's a pic that shows three seeds (with coverings) of G. globosa:
Now, I must find my own 'Pink Zazzle' !!!