providing it in in european airspace and not crossing any international borders
That part is totally irrelevant. If you are licenced to fly the aircraft, it doesn't matter which country you are flying it in in terms of it being logable.
can I log IFR hours on this aircraft?
Well that comes down to the question to you have an IR that is valid to fly that aircraft in that airspace? If so, then you log your time in whatever capacity you served. If not, then you can't log it as you can't fly it under IFR.