An old dart, I see, injected dough sweetener (6,5)

I believe the answer is:

manuka honey

I'm a little stuck... Click here to teach me more about this clue!

'an old dart i' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.

'injected dough sweetener' is the wordplay.
'injected dough' becomes 'manuka' (I can't justify this - if you can you should believe this answer much more).
'sweetener' becomes 'honey' (honey is a kind of sweetener).
'manuka'+'honey'='MANUKA HONEY'

'see' acts as a link.

Can you help me to learn more?

I've seen this clue in the Sydney Morning Herald.

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