Pat the chicken breasts dry and season with 1 teaspoon kosher salt and 1/4 teaspoon ground black pepper; cut into 1/2-inch pieces and place in a zipper-style plastic bag.
Make the slurry: in a small bowl whisk together 1 tablespoon cider vinegar, 1 tablespoon cornstarch and the egg white until smooth. Pour the slurry over the chicken in the bag, seal, shake to coat, and refrigerate 15–30 minutes.
In a large bowl whisk together 1 cup all-purpose flour, 1/4 cup cornstarch, 1 1/2 teaspoons baking powder, 2 teaspoons onion powder, 2 teaspoons granulated garlic, 1 tablespoon granulated sugar, 2 teaspoons kosher salt, 1/2 teaspoon ground black pepper and 1/4 teaspoon cayenne pepper.
Add 1/4 cup water to the dry mixture and rub with your fingers until the mixture forms tiny craggy bits and holds like damp sand when squeezed.
Stir in 1 cup finely crushed Fritos to the flour mixture and mix to combine.
Remove the chicken from the fridge and place half the pieces into the flour–Fritos mixture; toss thoroughly so each piece is coated, then spread the coated pieces on a rimmed baking sheet.
Add the remaining 1/4 cup flour and 1/4 cup crushed Fritos to the bowl, whisk to combine, then coat the remaining chicken pieces the same way and place them on the baking sheet.
Pour oil into a Dutch oven to about 1 inch deep and heat over medium-high until the oil reaches 400°F (about 205°C).
Line a rimmed baking sheet with paper towels. Working in batches, carefully add half the coated chicken to the hot oil using a slotted spoon or spider and keep the pieces moving; fry 2–3 minutes until golden brown and cooked through. Transfer to the paper towel–lined sheet.
Reheat the oil to 400°F if needed and fry the remaining chicken the same way, then transfer to the prepared sheet. Let the chicken rest 5 minutes before serving with your favorite dipping sauce.