Herb cookie filled with ganache longing to be eaten! (7)
I believe the answer is:
oregano
'ganache longing to be eaten' is the definition.
I can't judge whether this definition defines the answer.
'herb cookie filled with' is the wordplay.
'herb' becomes 'gan' (I can't justify this - if you can you should believe this answer much more).
'cookie' becomes 'oreo cookie' (brand of cookie).
'filled with' indicates putting letters inside.
'gan' inserted inside 'oreo' is 'OREGANO'.
Can you help me to learn more?
(Other definitions for oregano that I've seen before include "that's aromatic" , "aromatic plant" , "leaves for season" , "Gear Ono up for the herb" , "Pizza herb" .)