Unless for some reason you cannot gain access to the roofspace above,
changing it to the conventional above ceiling wiring arrangement would
sound the easiest thing to do.

If it must remain as the current arrangement, a small circular disc of
wood behind the ceiling fitting (with a suitable hole drilled in the
side) and painted the same colour as the ceiling would be a simple
solution.

Any surface-mount cable should be in trunking to comply with wiring
regs of course.