I once had a really important note on the iPhone note app that I accidentally deleted

[Flac]

Is there no way to recover it?

 

[PhiLLoW]

You can kill your Wi-Fi or Data connection before it syncs with icloud. The "old" document will be still online. Or you boot your Mac without internet connection.

If it already happens some time ago - i don't think there is any way to recover it.