You can sell food for fundraising up to 20 times per year without registering under the Food Act. This includes the sale of cakes, biscuits, lollies etc.
Every one selling food must make sure it is safe and suitable, even if you dont need to register. You can still be checked and held accountable if you make people sick.
Visit the MPI web site and use the "Where do I fit" tool
http://www.mpi.govt.nz/food-safety/food-act-2014/where-do-i-fit/
from there, all the necessary forms and information can be found on the Waipa District Council's website
http://www.waipadc.govt.nz/our-services/environment-and-health/Food/Pages/default.aspx
It is the responsibility of persons selling food to ensure they register a Food Control Plan or National Programe