Cut washed, unpeeled potatoes into french-fry shaped pieces.
Mix together peanut oil, lime juice, fish sauce, peanut butter, salt, pepper, garlic, cayenne, coriander powder, cumin, and onion powder in a large ziplock bag or mixing bowl.
Add cut potatoes and mix around, making sure potatoes are evenly coated.
Allow to marinate in this mixture for 1 hour.
Preheat oven to 400 degrees F.
Line baking sheet with aluminum foil (this makes for easy clean-up later!); pour small amount of vegetable oil on foil and wipe around with paper towel.
Spread potatoes in single layer on foil, without potatoes touching, if you can.
Bake for 40-45 minutes, turning potatoes once or twice during cooking.