First, it doesn’t ask you for confirmation, and second, it moves the deleted sticky notes into the trash folder. So, if you removed it just now, Outlook Trash is your best bet to recover it.

Retrieve lost or deleted email files from Microsoft Outlook (PST), Outlook Express (DBX), Exchange Server (EDB), etc. Recover ...

Outlook offers an option to restore ... ‘Move Folder’ and then move it to the ‘Tasks’ folder to automatically restore the deleted to-do lists and see it again in your To-Do application.