The club’s impressive summer in the transfer market has seen the club enhance their squad for what appears to be a tilt at the title.
The arrival of the Dons striker comes on the back of their capture of Peterborough United attacker Danny Lloyd.
The 30-year-old forward joined the Dons from Oldham Athletic in 2014 and has scored 87 goals in 194 appearances.
“We wish Adam all the very best with his new venture and it is always with a heavy heart when you lose a good player who is also a really good person,” Aberdeen manager Derek McInnes told the club’s website.
“Since I signed Adam four and a half years ago, he has given us nothing but good value and has been a fantastic boy to work with.”