Waste time producing sweet (6)
I believe the answer is:
trifle
I believe this clue is a double definition.
'waste time' is the first definition.
(thesaurus)
'sweet' is the second definition.
(trifle is a kind of sweet)
'producing' acts as a link.
(Other definitions for trifle that I've seen before include "Sweet - little thing" , "Party dessert" , "Cold dessert" , "Knick-knack" , "nothing?" .)