Gonna have to stretch a bit since most are not strictly "classical" music with electronic instruments, but I second the list by @acman3
Apex Twin is the arguably the grandaddy of modern electronic music, and an excellent place to start. he ranges from accessible/beautiful sombre ambient (Brian Eno), to lighthearted ambient techno, to insane club music, to scary nightmarish soundtracks, with a whole world of original thought between. Always interesting.
Ryuichi Sakamoto, Nils Frahm and Floating Points hit that cross section between Classical and electronic you were specifically asking for IMO
Four Tet is a personal favorite, not quite in the classical realm, but so excellent
I'd also recommend GAS (Wolfgang Voigt) and Daedalus (Alfred Darlington)
Not 100% electronic or classical, but might be of interest here: Colin Stetson. He is a genius saxophone player. Check out his reworking of Gorecki's Sorrow. his other work is great too.
Also, Max Richter.