Using a fork, poke holes all around the sweet potato. Brush a thin layer of olive oil all around the sweet potatoes and sprinkle with salt.
Place the potatoes in the air fryer basket at cook for 30-35 minutes, or until fork tender. If you want your potatoes to have a soft outside, turn off the air fryer and leave the potatoes in the closed basket for 2-3 minutes. If you like the skin crispy, remove the potatoes as soon as they are finished cooking.
Remove the potatoes from the air fryer and slice open by making a horizontal and vertical slice (like a plus sign). Then use your fork to mash and open the sweet potato. Add a cube of butter and a sprinkle of cinnamon before serving.