How do you best mount a cabinet face frame?

I have already made a carcass and it has raised panels on both sides. I
now want to use a face frame to mount 3 doors (previously was just
going to edge mount). How should I attach the face frame so that I dont
have to drill or mar up the raised panel sides? The side railes are
about 2" wide using 3/4" oak.

I was just going to build the face frame as a unit then attach to
carcass. Face frame will probably be about 1.5" wide using 3/4" oak. I
have a biscuit cutter I could use to biscuit around the edge of the
carcass w/matching cuts in back of frame, then glue and clamp. But
since there would be constant weight of doors/frame pulling frame away
in line with the bisquits, it doesnt seem like the bisquits provide
much strength in that orientation and its all glue for strength with no
mechanical attachment.

Thanks for any tips.