I am a corn producer producing pasta (8)
I believe the answer is:
'pasta' is the definition.
(macaroni is a kind of pasta)
'i am a corn producer' is the wordplay.
'producer' indicates anagramming the letters.
'iamacorn' with letters rearranged gives 'MACARONI'.
'producing' is the link.
(Other definitions for macaroni that I've seen before include "finishes off burlesque verse", "Omani car (anag)", "Italian fare", "Short narrow tubes of pasta", "2 [PASTA]".)