Spiess agreed professional terms with the club after completing a youth scholarship and is one of the club's most exciting young prospects.
The German goalkeeper’s impressive performances in the youth team attracted the interest of numerous top-flight teams but he decided to remain at Meadow Lane with the hope of playing first team football.
Spiess made his professional debut on the final day of the 2011.12 season from the bench and went on to show that he is stern competition for the main spot between the sticks the following campaign.
He made seven impressive appearances, which included Man of the Match showings against Leyton Orient and Crewe Alexandra.
It was to the County supporters' delight that he agreed a new long-term contract with the club in July 2013.