Pies can include top flavouring (5)
I believe the answer is:
spice
'flavouring' is the definition.
(I know that spice is a type of flavouring)
'pies can include top' is the wordplay.
'can' indicates an anagram (I've seen 'canned' mean this (canned can mean drunk)).
'include' indicates putting letters inside.
'top' becomes 'c' (I can't justify this - if you can you should give a lot more credence to this answer).
'pies' with letters rearranged gives 'spie'.
'spie' placed around 'c' is 'SPICE'.
Can you help me to learn more?
(Other definitions for spice that I've seen before include "Flavouring substance" , "Something providing excitement" , "Aromatic flavouring" , "eg Mace, ginger, Posh" , "Pungent substance to flavour food" .)