Preheat the oven to 400 degrees F (200 degrees C). Line a baking pan with parchment paper.

Combine flour, 1 pinch cayenne, 1 pinch garlic powder, salt, and pepper in a shallow bowl. Beat eggs in a second bowl. Combine panko bread crumbs with remaining 1 pinch cayenne, remaining 1 pinch garlic powder, salt, and pepper in a third bowl.

Dredge chicken thighs in flour mixture; shake off excess. Dip into egg, then press into panko mixture to coat both sides. Transfer breaded thighs to the prepared pan.

Bake thighs in the preheated oven until golden brown and no longer pink in center, about 40 minutes. An instant-read thermometer inserted near bone should read 165 degrees F (74 degrees C).