Hi Ralf!
Thanks for getting in touch with us!
First, please let me note that we are fairly limited in how much support we can give for custom development questions like that.
That said, we always like helping out and at least point users into the right direction as much possible.
I’ve just tried setting up a notification using Better Notification and it seems only possible to send to the event author, which in some cases it is the same as the organizer.
However, I don’t see a built-in setting to send an email to the event Organizer.
We do have a snippet you can use to send a copy of the ticket email to the event organizer:
https://gist.github.com/vicskf/c807167bd0a89a13af7f9ad8d351d184
You can use it as a starting point to create some custom coding to achieve what you are looking for.
I hope that helps. Let me know if any follow up questions.
Best,
Victor