Position one oven rack on the upper shelf and another rack on the lower shelf of your oven. Preheat the oven 400 degrees F. Line two baking sheets with parchment paper.
Next, add the egg white to a large mixing bowl and whisk it briskly until it becomes foamy.
Peel the potatoes (or leave them unpeeled if preferred) and cut them into sticks that are about 1/4 to 1/2 inch in diameter and 3-inches long. They should resemble french fries. Try to cut the sweet potatoes as uniformly as possible so that the fries bake evenly.
As you cut up the fries, add them to the bowl with the egg white and toss them until they’re all coated evenly.
Next, drizzle the oil over the potato sticks in the bowl and toss until the oil is evenly distributed.
In a small bowl, mix together the cinnamon, paprika, salt and pepper.
Sprinkle the spice mixture over the fries in the bowl and toss to coat the fries. Try to get them as evenly seasoned as possible.
Divide the fries equally between the two baking sheets and space them out evenly on each sheet so that they’re not overcrowded. This is key for getting them to crisp up.
Bake the fries for 20 minutes. Remove the pans from the oven, and then using a large spatula, flip the fries.
Arrange the fries into a single layer again to ensure that they aren’t overlapping. If any of the fries look like they’re browning too quickly, move them towards the front or centre of the baking sheet.
Return the baking sheets to the oven, alternating their positions on the upper and lower racks.
Continue baking until the fries are crisp and lightly golden on the outside and soft and tender on the inside. This should take about 5 to 10 additional minutes, depending upon your oven and the size of your fries. The ends may look crispy and dark on some of the fries and you should see some lighter brown spots in a few places.
Remove from the oven. Season with additional salt and pepper, to taste. Serve immediately.