Dear Joseph
Thank you for your recent enquiry via email concerning Kit Kat.
Unfortunately, there is no easy answer to your enquiry. Such answer as there is comes from the Food Labelling Regulations 1984, of which the definitions given for a biscuit are far from satisfactory.
Kit Kat in all formats, does in fact meet the criteria for both a 'biscuit and for 'chocolate' confectionery. It would be pedantic and wrong to say that it meets one classification, to the exclusion of the other. The other important consideration is that Twix suffers from precisely the same problem. It is not an issue that is exclusive to Kit Kat, or indeed any number of similar products. What characterises them is both biscuit material and chocolate.
The other consideration is the form in which these products are presented and marketed. Two fingered Kit Kat has a different target market and notional 'end use' than the Four Finger or Chunky version. Four fingered and Chunky is an impulse purchase for all ages and regarded as a snack or break product, where as the multipacks, especially the Two fingered variety is purchased as a planned snack and regarded as a biscuit.
Kind regards,