Green’s Dictionary of Slang

pinner n.3

also pinroll
[pin n. (1c) + roll-up n.2 (1)]

(drugs) a very small marijuana cigarette.

[US]‘Jennifer Blowdryer’ Modern English 79: skinny joints (n): New York PInner [...] Toothpick.
[US]Bentley & Corbett Prison Sl. 75: Pinroll also Pinrolled Joint and Pinner Used to indicate the small size of a marijuana cigarette.
[US]Other Side of the Wall: Prisoner’s Dict. July [Internet] Pinner: A marijuana cigarette the size of a toothpick.