Not a fan of having to open chrome and type 5minute timer every time I want to cook dinner. Is there no timer app for notification centre or menu bar yet?
I came to post this same question. Sorry I don't have the answer. I'm surprised this hasn't been made yet!
EDIT:
Until a notification centre widget is released, I'm going to be using this Alfred workflow, which really works just as well if not better than what I was looking for anyhow.
I use Siri all the time for timers, since it's way easier to just say "Hey Siri, set a timer for 5 minutes" than launch any app and tap stuff. Have you tried it?