Produced wriggly eel in cake! (9)
I believe the answer is:
madeleine
'cake' is the definition.
(I've seen this before)
'produced wriggly eel in' is the wordplay.
'produced' becomes 'made' ('make' can be a synonym of 'produce').
'wriggly' indicates anagramming the letters (I've seen this in other clues).
'eel'+'in'='eelin'
'eelin' is an anagram of 'leine'.
'made'+'leine'='MADELEINE'
(Other definitions for madeleine that I've seen before include "Item on sweet menu" , "Small sponge cake" , "Woman" .)