Oooooh the memories!!! I used to buy this from a market when I lived up north but have never seen it anywhere else!
Thanks for the site missrandom.....shame its all sold out at the moment :(
Psychick the brand name's "Marshmallow fluff" i think. It comes it a bigger than average transparent jar with the word "Fluff" in a huge font on the label.
Pretty sure it was this one: http://www.marshmallowfluff.com/