Preheat oven to 400 degrees. Line a large baking sheet with parchment paper.
Cut chicken breasts into thin strips, about one inch wide. Longer sections can be cut in half to have uniform pieces.
Combine whole wheat flour, cajun seasoning, cayenne pepper, and onion powder. Set aside. Beat eggs in another shallow dish. Pour Panko and breadcrumbs into a third shallow dish.
Coat each chicken strip in flour, shaking off any excess. Then, dip in egg and let any excess drip off. Then generously roll in the breadcrumbs, shaking off any excess. Add more Panko to the dish if you are running low.
Place the chicken strips on the prepared baking sheet. Drizzle the chicken lightly with olive oil or spray lightly with nonstick spray to ensure the coating stays on chicken.
Bake for 10 minutes. Flip chicken and bake for 10 more minutes until coating is crispy and chicken is cooked through. If you like them more brown, bake longer. Slice the warm chicken. Set aside.