Preheat oven to 450°F. Line two baking sheets with parchment paper and set aside.
In a large bowl, toss the sweet potato fries with avocado oil—making sure every fry is well-coated.
Sprinkle on the arrowrroot powder, and toss until every fry has a fine dusting.
Spread the fries in one even layer on the prepared baking sheets, making sure that none are touching. The more space there is around each fry, the crispier they will become.
Bake in the preheated oven for 15 minutes, flip the fries and rotate the pans, and then bake for an additional 5-10 minutes, or until the fries are brown and crispy. Season with salt immediately upon bringing out of the oven.
To reheat leftovers: Arrange in a single layer on a parchment-covered baking sheet and bake at 450°F for 5-8 minutes, or until warmed and crispy.