The 20-year-old, who made nineteen appearances for the Silkmen last term, will now stay at the Moss Rose for the 2016/17 season.
Local lad Cowan, came through the Silkmen’s youth team to earn a place in the first-team for the 2014/15 season after making his professional debut in the final game of the previous campaign.
After making nineteen appearances during his debut year, Cowan proved to be a valuable member of John Askey's squad again last term and will now look for further first-team action after signing his new deal.