Cinnamon rolling is a handshake whereby two or more people all put their right hands in together
so their fingertips touch, wiggle their fingers then
cry "CINNAMON ROLLLLL!" while curling their arms round
so that all participants are making
a big spirally shape
with their arms. It was introduced by the Australian psych
band Pond, and has since been adopted by UK bands Swim Deep and Peace among others, often
as a pre-show ritual.
For an example, see Freshly Squeezed's interview
with Swim Deep on youtube, skip to 3.13.
Great for making friends with people
at gigs "Hey guys! Cinnamon rollll!" At this point they either
have no idea what you're on about
(in which case
explain) or they do, and you bond over this shared piece
of pop culture knowledge.