Cake decorator brought in ice-cream for guide (8)
I believe the answer is:
cicerone
'for guide' is the definition.
(cicerone is a kind of guide)
'cake decorator brought in ice-cream' is the wordplay.
'cake decorator' becomes 'icer' (I've seen this in another clue).
'brought in' is an insertion indicator.
'ice-cream' becomes 'cone' (I've seen this in other clues).
'icer' placed inside 'cone' is 'CICERONE'.
(Other definitions for cicerone that I've seen before include "who shows visitors round?" , "A guide supplied by rice cone, strangely" .)