Plug by old railway for baked item (4,6)
I believe the answer is:
puff pastry
'baked item' is the definition.
The definition suggests a singular noun which matches the answer.
'plug by old railway' is the wordplay.
'plug' becomes 'puff' (I've seen this before).
'by' means one lot of letters go next to another.
'old' becomes 'past' (similar in meaning).
'railway' becomes 'ry' (abbreviation for railway).
'puff'+'past'+'ry'='PUFF PASTRY'
'for' is the link.
Can you help me to learn more?
(Other definitions for puff pastry that I've seen before include "It's used for vol-au-vents" , "Lightweight food" .)