Cream filling, a copper says (5)
I believe the answer is:
reads
'says' is the definition.
('read' can be a synonym of 'say')
'cream filling a copper' is the wordplay.
'filling' means to look at the middle letters (the letters which fill the word).
'a copper' becomes 'ds' (I can't explain this - if you can you should give a lot more credence to this answer).
The middle letters of 'cream' are 'rea'.
'rea'+'ds'='READS'
Can you help me to learn more?
(Other definitions for reads that I've seen before include "Scans" , "Peruses" , "Looks at and undertsands the written word" , "Studies (at university)" , "Understands written language" .)