Grind the nuts in a food processor until most pieces are about the same size and fairly small. A mix of sizes is okay but the bulk should be uniform.
Add the cinnamon and pulse until it is well-distributed.
Add the dates and grind until the dates are in pieces about the same size as the nuts and you cannot see any whole dates or large pieces.
Pinch marble-sized pieces of the mix and squeeze them together until they hold together in a ball--and that's it.
I keep mine in the fridge. The first batch I made, I didn't use cinnamon but I did roll them in shredded coconut. They were delicious, too.