Maße is the plural. In + Dativ, it should be besonderEN, not besonderEM. if using Maß, then with Dativ singlular Neutrum Word, it goes with besonderEM Maß.
Could any of you help explain why in besonderEM Maße still seems to be correct? As such writing displayed in my Deutsch textbook.
Many thanks in advance!
Sincerely, Canny