Let the cake return to room temperature before serving, if possible. (illmakeitmyself.net)
The next morning, pull them out and let return to room temperature, about 1 hour, before proceeding. (bookpage.com)
You can serve right away or refrigerate for 1 - 6 hours and then remove before serving, allowing enough time for it to return to room temperature for optimum flavor. (kneadtocook.com)