Preheat the oven to 425 degrees F (220 degrees C). Line a baking sheet with aluminum foil; spray with cooking spray.
Place sliced potatoes in a colander; sprinkle sugar over potatoes. Set aside until liquid is released from potatoes, 20 to 30 minutes. Drain liquid and dry potatoes well.
Mix potato slices, olive oil, garlic powder, salt, and black pepper in a resealable plastic bag until evenly coated. Spread coated potato slices in a single layer, leaving space around each potato, on the prepared baking sheet.
Bake in the preheated oven for 20 minutes; flip fries and continue baking until crisp and browned, about 20 more minutes.