Ah, situation clearifies now! BDV65B is NOT a MOSFET!! Just a simple darlington.

Snubber circuit should be a series circuit consisting of R and C. Only in radio controlled applications, like model car racing, I have seen snubber circuits without R.
C should be about 10...100nF and R about 10...100Ohm. It highly depends on your motor, of course. If you make a search about 'snubber' you will surely find formulas helping to design it correctly.
Without R, power is not much dissipated, even if free wheeling diodes are turning-on. C only limits rise time of this overvoltage spike, in order to give free wheeling diodes enough time to turn-on.
With R some power is also wasted in R and ringing is damped.
For every motor and every working condition there's an optimum choise of R and C.
I think, there are others here, knowing much more about snubbering than me?

Kai