In lg bowl, whisk together buttermilk, mustard and hot sauce. Add chicken to mix, toss to coat evenly. Cover, refrigerate 1 hr to marinate.
Heat oven to 400. Lightly spray a baking sheet w/ cooking spray. In lg shallow bowl, combine panko crumbs, cornmeal, paprika, garlic powder, salt and ground red pepper. Mix well.
Remove chicken from marinade. Roll the chicken into panko crumb mix evenly to coat. Place chicken on a rack on baking sheet. Spray chicken w/ cooking spray. Bake about 45 mins, or until chicken is cooked through.