Amankwaa was followed by clubs such as Ajax and Arsenal in 2012, but he wanted to play for FC Copenhagen.[4] He was also on a trial at Chelsea and he revealed in 2012 that he had more trial offers, but he rejected them.
Amankwaa was promoted permanently to the first team in 2013.[8] The contract was extended once again in May 2014 until 2017.[9] He played 9 league matches for the first team in the 2012–13 season, and 15 matches in the second season.
In May 2015, Amankwaa suffered from an achilles tendon rupture and was out for about half a year.[10] He went back on the pitch in October 2015, but just one month later he was back on the sideline again. He injured his meniscus and that resulted in an operation, and was out for the rest of the year.[11] Due to all these injuries, he only played 7 league games in that season.
The injuries continued in the next season and he was operated in October 2016 for a knee injury,[12] which kept him out for the rest of the year. His contract was extended in November 2016 until 2018.[13]
Heart of Midlothian
On 25 January 2018, Amankwaa joined Heart of Midlothian (Hearts) on a free transfer, having been allowed to leave Copenhagen before the end of his contract.[14] He signed an 18-month contract with the Scottish Premiership side.[15]
SønderjyskE
With limited success in Scotland, Amankwaa went home to Denmark, signing a one-year contract with Danish Superliga-side, SønderjyskE.[16][17] He left the club by the end of 2019.[18]
Hobro IK
Amankwaa remained without club until 31 October 2020, where he signed with Danish 1st Division club Hobro IK for the rest of 2020.[19] After three years, Amankwaa left Hobro in June 2023.[20]