Place Doritos in a zip-top bag and crush with a rolling pin or pulse in a food processor until they resemble coarse breadcrumbs, then pour into a shallow bowl.
Set up three bowls: one with seasoned flour (garlic powder, onion powder, paprika, salt, pepper), one with whisked eggs and milk, and one with the crushed Doritos.
Dredge chicken strips in flour, dip in egg, then roll in Doritos, pressing gently so the coating sticks.
For baking, cook at 400°F (200°C) on a greased sheet for 18–20 minutes, flipping halfway. For air frying, cook at 375°F (190°C) for 10–12 minutes, flipping halfway. For deep frying, heat oil to 350°F (175°C) and fry 3–4 minutes per side until golden, then drain on paper towels.