Can the Rice Krispie Squares be made in advance and either stored in an airtight tin or maybe even in the freezer?
Nigella's Rice Krispie Squares are chocolate flavoured bars that are slightly soft but not quite as sticky as the type made with marshmallows. The squares can be made ahead and stored in an airtight container at cool room temperature and are best within 3 days of making.
The squares can be frozen in airtight containers for up to one month. If you are stacking the squares in boxes then put a piece of baking parchment (parchment paper) in between each layer. Alternatively, wrap each square individually in clingfilm (plastic wrap) and store in resealable bags, being careful not to crush the squares when they are in the freezer. To thaw the squares, remove them from the box and leave at room temperature for about one hour.