Preheat the oven to 450 degrees.
Halve the sweet potatoes lengthwise and cut each half into 3 long spears. Place them on a sheet pan and toss with the olive oil or coconut oil. Spread the potatoes in one layer. Combine the cinnamon and salt. Sprinkle on the potatoes.
Bake for 15 minutes and then turn with a spatula. Bake for another 5 to 10 minutes, until lightly browned. Serve hot.