For those wishing to include buttercream, blend 300 g of icing sugar with 150 g of softened butter until the mixture is light and airy. To create a crumb coat for fondant icing, adjust the quantities accordingly, keeping to a 2:1 icing sugar to butter ratio. Store any leftover Victoria Sponge in an airtight tin for up to a week. For freezing, wrap the sponges tightly in cling film and foil before they are sandwiched with jam. Thaw at room temperature and consume within three months. Do not refreeze once defrosted. For precise results, it is recommended to use digital scales rather than cup measures.