Asperities ruined cake shop (10)
I believe the answer is:
patisserie
'cake shop' is the definition.
(I've seen this before)
'asperities ruined' is the wordplay.
'ruined' indicates an anagram.
'asperities' is an anagram of 'PATISSERIE'.
(Other definitions for patisserie that I've seen before include "food shop" , "store for Brownies?" , "Tart collection" , "where cakes are sold" , "Cake and pastry shop" .)