Sweet packet (4)
I believe the answer is:
mint
This clue is a double definition.
'sweet' is the first definition.
(I know that mint is a type of candy)
'packet' is the second definition.
(both can mean a lot of money)
(Other definitions for mint that I've seen before include "Where money coins are manufactured" , "Coin-making place or nice lamb sauce" , "fortune" , "sweet > factory?" , "packet" .)