Prisoners would be assembled before the Happiness Patrol firing squad in the yard, but the patrol would then be dismissed and the victim would think he'd been pardoned. A pipe would then descend over them and from his Kandy Kitchen the Kandyman would operate levers to direct the Surprise. Afterwards, the Surprise would flow into the pipe and smother the victim to death.
Like any method of execution, if the mechanics of the Fondant Surprise failed, constitutional rules of the system prevented the Surprise from being repeated. However, a substitute execution could be carried out. (TV: The Happiness Patrol)