I think "mignonnerie" is a possible translation but it not a word really used in French.

I probably would translate it by "côté mignon".

"Mignon" is the translation for "Cute", but cuteness doesn’t really have one.

You can either use made up words like "Mignonnerie".

Or you can say that it is cute. "C’est mignon." "C’est trop chou !"

But it might be different from what you need depending on the context in which you want to use this. Did you have a particular sentence or idea in mind ?