Source: Tal'Dorei Campaign Setting Reborn

Prerequisite: Spellcasting feature from a class that prepares spells

You've developed the ability to instantly recall an unprepared spell in moments of sudden necessity.

As a bonus action, you prepare a spell of 1st level or higher from your spellbook (if you're a wizard) or from your class spell list (if you're not a wizard). This spell must be of a level for which you have spell slots, and it replaces another spell of an equal or higher level that you had previously prepared.

Once you use this feat to recall a spell, you can't do so again until you complete a short or long rest.