Rich dessert put back in imperial centre (6)
I believe the answer is:
eclair
'rich dessert' is the definition.
(I've seen this in another clue)
'back in imperial centre' is the wordplay.
'back' says the letters should be written backwards.
'in' says the answer is hidden in the clue.
'rialce' is hidden in the letters of 'imperial centre'.
'rialce' written backwards gives 'ECLAIR'.
'put' acts as a link.
(Other definitions for eclair that I've seen before include "Dainty" , "comedian Jenny?" , "Lacier type of confection" , "A long choux cake" , "Long cream puff" .)