Preheat the oven to 400 degrees F (200 degrees C). Line a half-sheet pan with aluminum foil. Place a baking rack on top.
Place corn flake crumbs in a bowl.
Mix teriyaki sauce, Sriracha sauce, paprika, rice vinegar, and sugar together in a large bowl until sauce has a thick consistency.
Place chicken thighs in the bowl with sauce. Tumble thighs together until completely coated. Smear sauce onto any bare spots and under any loose flaps of skin.
Place 1 thigh into the bowl with corn flakes. Spoon crumbs on top using a tablespoon. Press crumbs onto thigh using the back of the spoon, pressing thigh down into crumbs to coat underside. Turn over and repeat pressing. Place onto the baking rack, skin-side up. Repeat with remaining thighs and crumbs, placing largest thighs in the corners of the rack to receive the most heat.
Bake in the preheated oven for 30 to 40 minutes depending on the size of thighs. Reduce oven temperature to 325 degrees F (165 degrees C) and continue baking, 15 to 20 minutes. Turn thighs over to help undersides crisp up. Bake until no longer pink at the bone and juices run clear, 15 to 20 minutes more. An instant-read thermometer inserted near bone should read 165 degrees F (74 degrees C).
Let thighs rest on the baking rack for at least 15 minutes before serving.