Fill a large bowl with cold water. Cut the potatoes in half crosswise. Using a mandoline, thinly slice each half into rounds. Transfer the potato slices to the water and let them soak for one hour.

Meanwhile, combine the brown sugar, salt, garlic powder, chili powder, and paprika in a small bowl. Line a work surface with a layer of newspaper and then a layer of paper towels.

Drain the potatoes and lay them in a single layer on top of the paper towels. Let stand until dry, about 30 minutes. Blot any damp spots with extra paper towels.

Pour two or three inches of oil in a large pot, such as a Dutch oven. Clip a thermometer to the side of the pot and heat over medium-high heat until the oil reaches 375°F.

While the oil in heating, transfer the potato slices to a clean, dry bowl and reline the work surface with a new layer of newspaper and paper towels. Line a large, flat plate with paper towels. Have ready a clean paper shopping bag.

Working in batches, fry the potato slices, turning once, until they are nicely browned, two to four minutes. Remove the chips as they are done with a slotted spoon and transfer them to the paper towel-lined plate.

From the plate, dump the chips into the paper bag and sprinkle with a little bit of the spice mixture. Give the bag a good shake to coat the chips. Dump the chips out onto the work surface lined with newspaper and paper towels and let them drain and dry completely.

Store the chips in an airtight container for up to a month.