There are several fanfictions out there where Harry is raised by Snape. You can try searching on fanfiction - specific websites like FanFiction.net or Archive of Our Own (AO3). Just type in 'Harry Potter raised by Snape' in the search bar, and you'll likely find a plethora of stories. Some might focus on the magical education Snape would provide Harry from a very young age, while others could delve into the complex relationship dynamics between them.
One popular fanfiction with this concept might be 'The Unthinkable' (this is just an example, not an actual well - known title with this exact plot). In many such fanfictions, it explores how Snape's personality would influence Harry's upbringing. Snape, being strict yet intelligent, could instill in Harry a different set of values compared to the Dursleys or even Dumbledore's influence in the original series.
I'm not sure of a specific fanfiction titled exactly like that, but the idea of Harry being raised by Snape is quite interesting. It could lead to a very different Hogwarts experience for Harry. Snape might be more protective of Harry in a way that he was never able to show in the original series. He could also pass on his knowledge of potions and the Dark Arts in a more hands - on way, which would make Harry a very different kind of wizard.