Xanathar's Guide to Everything, pg. 165
Skill Empowerment
5-level
Transmutation
Casting Time 1 Action
Range Touch
Duration 1 Hour
Components V, S
Damage Type: Buff + Utility
Saving Throws: None
Description: Your magic deepens a creature’s understanding of its own talent. You touch one willing creature and give it expertise in one skill of your choice; until the spell ends, the creature doubles its proficiency bonus for ability checks it makes that use the chosen skill.
You must choose a skill in which the target is proficient and that isn’t already benefiting from an effect, such as Expertise, that doubles its proficiency bonus.
Class(es): Bard, Inventor, Sorcerer, Wizard