Bring a large pot of water to a boil. Add pecans and blanch until slightly tender, about 3 minutes. Drain and transfer to a large bowl. Add powdered sugar and mix until completely incorporated.

Thoroughly dry pot and return to stove. Fill with oil making sure pot is big enough so 2 quarts of oil only comes up about half way. The oil will bubble up dramatically when you add the pecans and you want to leave lots of room. Attach a deep fry thermometer to the side and heat oil to 350°F over medium heat. Meanwhile, combine salt and cayenne in a small bowl and have ready a baking sheet.

Give nuts another stir to coat them in the sugar and then using a metal slotted spoon or a spider scoop up a spoonful of nuts, letting any excess moisture drip back into the bowl. Carefully slide nuts into the hot oil and repeat until you have about 1-2 cups worth in the oil. You want to give the nuts plenty of room to move about in the oil and not clump up with each other.

Fry nuts, stirring occasionally, until very brown, about 5 minutes. Remove with the spider, letting any excess oil drip back into the pot, transfer to the baking sheet and spread out to a single layer. Immediately sprinkle with salt mixture and let cool to harden, then push to one side of the baking sheet. Once oil has returned to 350°F, repeat with remaining nuts.