The 17-year-old joined the Reds last summer from Hoffenheim in Germany and spent the season with the U18s squad.
An attacking midfielder with an eye for a goal and an ability to glide past opponents, Frauendorf played a role in some of the biggest moments of the Academy's 2020-21 season.
He opened the scoring in the first minute in a derby victory against Everton at Kirkby, before scoring the winner in the FA Youth Cup semi-final against Ipswich Town and grabbing another in the subsequent final defeat by Aston Villa.
Born in Ethiopia, he moved to Germany with his family and has represented his new home as a youth international.