Catches sight of banks of Eccles cakes in the bakery's window (6)
I believe the answer is:
espies
'catches sight' is the definition.
(I've seen this before)
'banks of eccles cakes in the bakery's window' is the wordplay.
'banks of' suggests removing the centre (the banks are the sides of the word).
'cakes in the bakery's window' becomes 'pies' (I am not sure about this - if you are sure you should believe this answer much more).
'eccles' with its centre removed is 'es'.
'es'+'pies'='ESPIES'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for espies that I've seen before include "Catches sight of" , "Spots" , "Sees (archaic)" .)