With a name like Passo della Mulatierra it’s safe to assume people have been crossing this pass for centuries. From Bardonecchia there is a gravel road all the way to the summit (2412 metres). One could also start from Beaulard and join this road half way up.
A 3D video of ride:
More than half the climb is through a nice forest. Plenty of hairpins. Sometimes a rough surface, sometimes painfully steep, but always rideable. Beautiful.

I climbed Passo della Mulattiera in 2016, but I made a wrong turn early on and ended up needing to scramble up a steep ski slope. So I was back to rectify that routing error.

This time, I took the correct route (see map at bottom). Above the tree line, it’s a touch less steep, but the surface is slippery. Fabulous views:
At Passo della Mulattiera is a huge barracks ruins. It was built in 1939.
The road ends at the pass. Over the top is a good quality hiking trail leading into a completely deserted, undeveloped mountain valley. At 2272 metres I reached Col des Acles. This is exactly on the French / Italian border. There is a beautiful old border marker:

Next, the riding becomes tougher. It is a signed mountain bike route, and how much you ride will depend on your technical ability. I had to walk quite a few stretches. Too tricky and steep for me …. but I am an awful mountain biker!

In 2016, I would keep descending until I reached a paved road at 1400 metres, exactly at the base of Colle della Scalla (Col de l’Echelle). This is a beautiful paved way to enter France. In the 2016 link above, I would ride up/down Scala.
However, this year, I decided to instead follow signs to Pian del Sole. A right turn less than half way down from Col des Acles. This was a fabulous decision. This immediately becomes a very rideable trail that gently descends as it crosses a bunch of ski slopes (see 3D video). About as much fun as I’ve ever had descending through woods.
At one point I even passed the ski slope used in the Torino/Turin Olympics in 2006. 🙂
Finally, my route rejoined the forested road I had initially climbed and I descentded back to the start. Only 26 kilometres, but 26 very challenging and beautiful kilometres. No people, no cars!