I just found this on ao3, and it’s adorable!
Happy Birthday Kakashi (12 words) by racven
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Relationships: Hatake Kakashi/Umino Iruka
Characters: Hatake Kakashi, Umino Iruka, Shiranui Genma, Mitarashi Anko
Additional Tags: Birthday boy wanna eat his present, happy birthday Kakashi!, late birthday fanart, Kakashi’s tardiness deserves this lateness
He just wanted a taste of it