Preheat the oven to 400°F. Line a baking sheet with parchment paper or lightly grease it with cooking spray.
In a large bowl, combine the crushed cornflakes, shredded cheddar cheese, garlic powder, onion powder, paprika, salt, and black pepper. Mix well to combine.
Set up a breading station: Place the flour in a shallow dish. In another shallow dish, whisk together the eggs and water.
Dredge each chicken breast in the flour, shaking off any excess. Dip it into the egg mixture, allowing any excess to drip off, then coat it in the cornflake mixture, pressing gently to adhere.
Place the coated chicken breasts on the prepared baking sheet. Lightly spray the tops with cooking spray or drizzle with olive oil for extra crispiness.
Bake in the preheated oven for 25-30 minutes, or until the chicken is cooked through and the coating is golden brown and crispy. The internal temperature of the chicken should reach 165°F.
Let the chicken rest for 5 minutes before serving.