This is a must-do thing on motorcycle. Etna by moto! You'll be driving the closest tarmac roads to smoky craters what you can get, (you can get closer, but you'll need an off-road bike). This takes 3 to 5 hours depending how long stops you'll do. Trust me, you do want to stop more than one time! Probably craters aren't included in your daily moto routes basis.
The Etna route starts from Nicolosi, which is in Catania province. Usually the road is clean, but sometimes when the Volcano is active you could find some ash on the roads (it's completely black) so watch out on curves. There is nice to stop and check couple craters. The first destination is Rifugio Sapienza (2000 meters from the sea level).
In Rifugio Sapienza you can even stop even bit longer, it's a kind of touristic village, you could take even a cable car to get closer to craters. It's really expensive, around 50€ a head so you might consider, maybe you prefer to ride a bike, right?
Then you'll come down a to Zafferana, if you're hungry you could get a 'pizza Siciliana' from the main square. From Zafferana you'll start going up again on the East side of Etna. Follow signs to Etna Nord and Piano Provenzano. This part is AWESOME! Nice stops here are Rifugio Citelli and Piano Provenzano, which was destroyed in 2002 by lava. There is skiing center during winters.
Then there is Etna North side. The road is a bit worse, it's a bit bumpy, but still okay. You'll arrive to Bronte where you could taste the famous Bronte's pistachio ice cream. The taste is excellent.
Head towards Adrano and Ragalna and Nicolosi again. Yes the circle is complete, and you are one big experience richer! Hope you enjoyed!