Cheese stores have cake (7)
I believe the answer is:
brownie
'cake' is the definition.
(I know that brownie is a type of biscuit)
'cheese stores have' is the wordplay.
'cheese' becomes 'brie' (Brie is an example).
'stores' indicates putting letters inside.
'have' becomes 'own' (to have something is to own it).
'brie' going around 'own' is 'BROWNIE'.
(Other definitions for brownie that I've seen before include "Benevolent elf; cake" , "sweet thing" , "confection" , "Junior Girl Scout" , "Benevolent helper" .)