Step 1

Preheat oven to 425° F, with racks in the upper third and lower third of the oven.

Step 2

Cut the sweet potatoes into ¼-inch thick french fry shapes. (You do not need to peel the sweet potatoes.)

Step 3

Place cut sweet potatoes in a large mixing bowl. Drizzle with the olive oil and toss to coat.

Step 4

Evenly sprinkle the cornstarch, chili powder, paprika, garlic powder, salt and black pepper over the sweet potatoes. Use your hands to rub the cornstarch and seasonings over the sweet potatoes, until you no longer see the cornstarch on the fries and the seasonings are evenly distributed.

Step 5

Divide the fries between two parchment paper-lined rimmed baking sheets. Arrange the sweet potatoes in a single layer on the baking sheets, with a little space in between each fry.

Step 6

Bake for 15 minutes, then remove the pans from the oven, and flip each fry over. Rotate the pans in the oven from top to bottom and bake for 10-20 minutes more, until fries begin to brown on the edges and become crispy. Serve immediately.