Maybe try promising you can have it if you want it, but only AFTER writing the syns in your log / diary.
Also, once I've had one choc or biscuit it awakens the cravings, so I try not to have any of those til the evening, otherwise I'll be craving them all day if I have it in the morning.
Also avoidance. It's back to school day today, and I know I need to avoid the staffroom as people bring left overs in and put them in there.
If they put chocs in unavoidable places I'll sit next to someone who doesn't eat them, and tell them I'b being good so they can bully me into sticking with it (I have two people inmind for this job - they're very bossy, and i'm supposed to be in charge of them - they'll love the opportunity to tell me what to do lol).