Frosts, as a cake (4)
I believe the answer is:
ices
'frosts as a cake' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ices that I've seen before include "Cold refreshments" , "ecorates with frosting" , "Freezes" , "Kills (slang) - sweets" , "Decorates cakes with frosting" .)