Ayew was part of the Swansea side relegated from the top flight in 2018 and spent a year on loan at Turkish club Fenerbahce before returning to Wales and becoming the talisman under Steve Cooper.
He has scored 17 goals as the club have reached the play-offs for the second successive season.
Asked how promotion would compare to scoring for Ghana at the World Cup finals and for Marseille in the Champions League, Ayew said: “It would be among the tops.
“I have grown to love the club and the fans and it would be a big achievement because it would prove I can do it at any level.
“I’ve followed a lot of players who have played at a really high level, come down to the Championship, and not succeeded.
“This has been a test to prove I can do it at any level and I’ve never doubted myself. In terms of me personally, this (promotion) would be very big. That’s the reason why I stayed with this team.”
Ayew’s trademark strike at Oakwell on Monday, finding space on his left foot to curl a shot into the far corner, gives Swansea belief they can go one better than last season and set up a Wembley final date against Brentford or Bournemouth.
Swansea took a 1-0 lead into their semi-final return at Brentford last season before losing 3-1 in west London.
“Last season we played well against Brentford here, but in the second game we gave it away in the first 20 minutes,” said Ayew, 31, as Swansea prepare to welcome 3,000 fans back to the Liberty Stadium after the easing of coronavirus restrictions.
“We’ve learned from that and we need to show we’ve grown up and want to be in the final.
“This season, we have become a complete squad who can win games when we don’t really play well. That’s something we couldn’t do last season.”