Cut your chicken into large chunks. Big enough for about two bites per nugget. Place your chicken pieces in a bowl, season it with salt and pepper and give it a toss. Cover the chicken with buttermilk, cover your bowl, and store it in the fridge for at least 2 hours or up to 24 hours.
When you're ready to make your chicken nuggets, preheat your oven to 450 F (225 C). Line a baking sheet with foil then pop a rack on top of that. Spray the rack with oil.
In a large mixing bowl, mix together all your remaining ingredients. Use tongs to pull out some chicken pieces from the buttermilk. I do about five pieces at a time. Toss the chicken in your bread crumb mixture. Make sure each piece is well coated. Transfer the coated chicken to your oiled rack.
Spray the chicken with your oil spray and bake for seven minutes. Pull the tray out of the oven and use your (clean) tongs to flip each piece over. Spray again with oil and bake for another seven minutes or until your chicken is cooked through.
Allow to cool for a few minutes before serving with your favorite dipping sauce.