These bars can be baked and stored un-iced, covered, in the refrigerator for up to 2 days. You can make the cream cheese icing ahead and store it in an airtight container in the refrigerator for up to 1 month, but don’t fold it with the whipped cream until you are ready to ice and serve the bars. Iced bars can be stored in an airtight container in the refrigerator for up to 4 days.