Sir Terry Scott advertising Curly Wurly in the He used to dress up as a schoolboy for the tv ads as well. The advert depicts how the recipe was changed so that the middle was softer, making the milk chocolate less likely to drop off.
UK - Cadbury's CurlyWurly - we got loads of these as Dad worked for Cadburys and the factory shop sold all the seconds off cheap. Curly Wurlys must have gone wrong a lot because we seemed to get loads of them. Not Curly Wurlys again Dad!