Spreads offered by boring building society, say (7)

I believe the answer is:
butters
'spreads' is the definition.
The definition and answer can be both things that one consumes for nourishment as well as being plural nouns.
Maybe there's a link between them I don't understand?
'boring building society say' is the wordplay.
'boring' means one lot of letters goes inside another (to bore something can mean to drill into it).
'building society' becomes 'BS' (abbreviation for building society).
'say' becomes 'utter' (to utter something is to speak or say it).
'bs' placed around 'utter' is 'BUTTERS'.
'offered by' acts as a link.
Can you help me to learn more?
(Other definitions for butters that I've seen before include "Brandy and Peanut, maybe" , "another name given to goats?" .)
