A spearmint flavoured confectionery that has a firm yet soft chewy texture, formed into the shape & size of a real spearmint leaf. Proudly made in New Zealand by Mayceys Confectionery Ltd.
Commonly referred to as "Mint Leaves" or "Fuck nah, bro".
Apparently still made with "Grandpa's recipe"
Never in history has a confectionery divided a nation as much as the Mayceys Giant Spearmint Leaves. Spearmint in itself is a very divisive flavour. This combined with the soft/hard chewy texture and has caused a cultural divide akin to the Marmite vs. Vegemite wars or Auckland vs the-rest-of-the-country wars. The love/hate relationship seems to span generations with no consistent basis
Spearmint Leaves are available throughout the country however it's not massively widespread. One can only assume that due to their divisive nature, some buying managers might not want these items on their shop's shelves.
Spearmint Leaves are available in most corner dairies, especially the ones that have been open for many decades. Dairies usually sell them as a buy-per-leaf option or a larger, 50 cent baggie or $2 sandwich bag option.

It's availability in supermarkets depends on the conglomerate you visit. Usually found in the standard confectionery aisle, bulk bin section or the impulse buy checkout section.
Travel Notes
When you stop at a dairy during your visit, be sure to pick up a bag of these. The country is curious to know if visitors from around the globe love or hate them.
Personally, they are fucking awesome.