I find this takes exactly the amount of time the cake takes to make, cook and cool. But do give the icing a stir with a spatula every now and again. Line the bottom of your springform cake tin ...

Need to troubleshoot? If your icing has too many air bubbles that are interfering with piping, try to remix it by hand with a rubber spatula until it smooths out. Royal icing is a type of icing ...