Now. There’s some discussion about whether it’s best to let the cookies cool entirely before icing. Personally, I am not a big fan of thick sugary icing, so I prefer to use about half as much icing and spread it on while the cookies are still warm. The icing doesn’t make quite as hard a shell that way, and that’s Patty’s preference, too. I also like to press one pecan half into the top of each cookie before the icing sets.