Mix the hot sauce and buttermilk and marinate your chicken tenders for as little as ten minutes, up to 8 hours.
Combine flour, egg, salt, pepper, garlic powder, paprika, cayenne, mayo and mustard to make a batter. Dip each chicken tender in the batter, making sure to coat them well.
Crush up the grape nuts cereal to the size of a normal breadcrumb and mix in thyme, oregano, salt and pepper. Dip each battered chicken tender in to the breadcrumbs, coating well. Press the breadcrumbs into the chicken.
Spray a baking sheet with cooking spray and lay each chicken tender down. Bake at 400 degrees for 10 minutes.