A fruit cake covered with marzipan and sugar paste icing will keep for up to a month in a cool dry place, simply covered with baking parchment. Do not store in a sealed plastic container as the cake may ‘sweat’ and go mouldy. If necessary store in a cake box or cake tin. A sponge cake covered with sugar paste icing will keep for up to a week in a cake box or cake tin, but do not store in a sealed plastic container. Do not freeze iced cakes as they will become sticky and wet when defrosted A royal iced fruit cake will keep for a year or even longer if kept in a cool dry place such as the top of a wardrobe. Store wrapped in baking parchment inside a cake box. Do not store in a sealed plastic container.