Sugarcoating (5)
I believe the answer is:
icing
'sugarcoating' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for icing that I've seen before include "Freezing" , "The sweetest part of the cake" , "Sugar coating - a danger to aircraft, on roads etc" , "piece of cake?" , "Attractive addition or bonus, as on cake" .)