When making your luscious cream cheese filling, you want to sweeten the deal by whisking in some sugar. You might be tempted to use granulated sugar in place of icing sugar. Don’t! If you use granulated sugar, you’ll end up with gritty sugar in your cream cheese mixture. Icing sugar is much finer and dissolves into the cream cheese when whisked in. If you can’t find icing sugar you can whizz up some granulated sugar in a food processor for a few seconds. It won’t be quite as good as icing sugar, but it works at a pinch.