Black spice crushed creates muscle (6)
I believe the answer is:
biceps
'muscle' is the definition.
(biceps is a kind of muscle)
'black spice crushed' is the wordplay.
'black' becomes 'b' (as in pencil classifications).
'crushed' indicates an anagram.
'spice' is an anagram of 'iceps'.
'b'+'iceps'='BICEPS'
'creates' is the link.
(Other definitions for biceps that I've seen before include "Upper-arm muscle" , "Arm workers" , "Large upper arm muscle" , "Muscle that flexes the forearm" , "Arm muscles" .)