Bring 10 cups water and 2 Tbsp. kosher salt to a boil in a large pot over high. Add 2 cups nuts, and cook until slightly softened, 30 to 45 seconds. Drain nuts, and spread on paper towels; cool 2 minutes.
Combine 2 Tbsp. light brown sugar, 1 tsp. cayenne pepper, and 1/2 tsp. each chili powder and kosher salt for spice mixture.
Meanwhile, pour canola oil to a depth of 1 1/2 inches into a Dutch oven. Heat over medium-high to 325°F. Toss together nuts and 1/3 cup powdered sugar in a bowl; stir until nuts are evenly coated with sugar and almost all excess sugar is melted. Carefully add coated nuts to hot oil; fry until lightly golden, about 3 minutes. Using a spider skimmer or large
Transfer hot nuts to a medium bowl, and toss with spice mixture. Cool 30 minutes.