Soak the sliced onions in buttermilk, salt, cayenne pepper, and seasoned salt for at least 2 hours.
Drain onions, reserving buttermilk. Mix beaten egg with the buttermilk. In a separate bowl, place flour and set aside. Crush the saltines and potato chips into a medium crumb. Combine with panko in a separate bowl.
Preheat oven to 375 and add oil into a cookie sheet with sides. Place cookie sheet into oven to let oil heat up.
Bread rings by first placing into flour, then into buttermilk/egg mixture, then into crumb mixture. Set onto a clean platter.
When all rings are breaded, place into hot cookie sheet and bake for 5-7 minutes, or until golden brown. Check frequently as the cooking time will depend on your particular oven.
Flip over and cook on other side until browned, about 5 minutes.
Remove and serve immediately.