Set oven at 350° F (180° C) for Baked Potato Fries and 430° F (220° C) for Sweet Potato Fries.
Cut the potatoes into thin strips about 1/2 inch (12 mm) wide, with the skin left on (optional).
Place potatoes in a bowl. Season with salt and pepper, if making baked potato fries. If making sweet potato fries, also add cornstarch, paprika and garlic powder, decreasing pepper to 1/8 teaspoon (1 gram). Toss.
Add oil, decreasing to 1 tablespoon (14 grams) if making the sweet potato variation, and toss again.
Place potato slices evenly on parchment-lined baking sheet large enough to ensure potatoes are not on top of each other.
Bake for 40 minutes or until golden brown. Turn the potatoes after 20 minutes and continue to bake.
Serve with ketchup or vegan mayonnaise.