Order what cream cakes? (6)
I believe the answer is:
behest
'order' is the definition.
(I've seen this before)
'what cream cakes?' is the wordplay.
'what' becomes 'eh' (sound used to ask 'what?' or 'pardon?').
'cream' becomes 'best' (I've seen this in another clue).
'cakes?' indicates putting letters inside (cake can mean to cover).
'eh' inserted into 'best' is 'BEHEST'.
(Other definitions for behest that I've seen before include "Order" , "(At someone's) command" , "Command, bidding" , "Command - Thebes (anag)" .)