Sweet note included in blessing (6)
I believe the answer is:
bonbon
'sweet' is the definition.
(bonbon is a kind of sweet)
'note included in blessing' is the wordplay.
'note' becomes 'nb' (**).
'included in' means one lot of letters goes inside another.
'blessing' becomes 'boon' ('boon' can be a synonym of 'blessing').
'nb' inserted within 'boon' is 'BONBON'.
(Other definitions for bonbon that I've seen before include "French sweet" , "a tasty sweet - in France" , "Sweetie" , "Confection" , "Candy, doubly good in France?" .)