Biscuit made by posh type on cooker (6)
I believe the answer is:
hobnob
'biscuit made' is the definition.
I can't tell whether this definition defines the answer.
'posh type on cooker' is the wordplay.
'posh type' becomes 'nob' (I can't explain this - if you can you should give a lot more credence to this answer).
'on' means one lot of letters go next to another.
'cooker' becomes 'hob' (part of a stove).
'nob' put after 'hob' is 'HOBNOB'.
'by' is the link.
Can you help me to learn more?
(Other definitions for hobnob that I've seen before include "Socialise (especially with posher people)" , "Mix socially with the biscuit" , "Socialise together, rub elbows with" , "Spend time together, socialise" , "Socialise familiarly" .)