Leave beginning of broadcast with plug for sweet treat (10)
I believe the answer is:
gobstopper
'sweet treat' is the definition.
The definition suggests a singular noun which matches the answer.
'leave beginning of broadcast with plug' is the wordplay.
'leave' becomes 'go' (to go is to depart or leave).
'beginning of broadcast' becomes 'bper' (I can't explain this - if you can you should believe this answer much more).
'with' is an insertion indicator.
'plug' becomes 'stop' (stop can mean to plug a gap).
'bper' placed around 'stop' is 'bstopper'.
'go'+'bstopper'='GOBSTOPPER'
'for' is the link.
Can you help me to learn more?
(Other definitions for gobstopper that I've seen before include "Large, hard spherical sweet" , "Large, hard sweet to suck" , "Big sweet" , "Hard round sweet" .)