In EASA land its hidden in EU documentation which I will try and find.
Meanwhile anything in the below list with HPA (High Performance Aircraft) next to it or a full multi-pilot type rating is classed as High Performance.
https://easa.europa.eu/system/files/..._List_Acft.pdf
The FAA have a different definition.
In EASA there are not many twin turboprops that aren't HPA, examples of non HPA are DHC-6, D228, D028, Skyvan etc generally those that aren't pressurised and wont top 230kts.