Material as popular with sweet coating (9)

I believe the answer is:

bombasine

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

'popular with sweet coating' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.

'material as' is the wordplay.
I cannot quite see how this works, but
'as' could be 'in' (I've seen this in other clues) and 'in' is located in the answer.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?

I've seen this clue in The Guardian.

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