This instantaneously took me back to my junior years at CH when I used to go to the tuck shop regularly to buy these strange and apparently rare culinary delicacies. Yum yum.
Actually the first several times that I bought space pencils, I didn't realise that you could eat the outside bit as well, and I spent ages squeezing the stuff out from the middle. What an exciting way to spend one's afternoon freetime. It certainly was when you were 11.
I remember how some people used to go there about three times a week and always came back with a big wooden box filled to the brim with sugar and fat. I think if money was no object I would have done the same!