Sweet Prime advert (5,4)

I believe the answer is:

cream puff

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

'sweet' is the definition.
The definition and answer can be both things that one consumes for nourishment as well as being singular nouns.
Maybe there's a link between them I don't understand?

'prime advert' is the wordplay.
'prime' becomes 'cream' (I am not sure about this - if you are sure you should believe this answer much more).
'advert' becomes 'puff' (as in a puff piece, type of advertisement).
'cream'+'puff'='CREAM PUFF'

Can you help me to learn more?

(Other definitions for cream puff that I've seen before include "Rich cake" , "Pastry confection" .)

I've seen this clue in The Telegraph.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.