Mix the smoked paprika, cayenne pepper, onion powder, garlic powder, baking soda, thyme, bouillon powder, salt, and pepper in a small mixing bowl.
Sprinkle 1 tablespoon of the spice mix evenly all around the chicken pieces. Reserve the remaining spice for later use.
Whisk together the buttermilk and eggs in a large bowl. Season with a pinch of salt and pepper.
Add the chicken pieces and toss to coat well. Let the chicken soak for at least 10 minutes or up to 1 hour.
Meanwhile, preheat the oven to 400F
In another separate bowl, combine the all-purpose flour, cornstarch, baking soda, and remaining spice mix. Mix well.
Prepare the pan by lining it with parchment or foil. Then place a wire rack over the lined pan. Be sure to spray the wire rack with cooking oil spray to prevent the chicken from sticking to the rack.
Remove chicken from buttermilk and let excess drip off. Coat each piece of chicken in the flour mixture, shaking off any excess before placing them on the prepared wire rack. Leave them to rest for 5 minutes until the flour is absorbed.
Optional: For a thicker exterior, you can coat the second time with the flour mixture. Arrange them on the rack and let them rest for 5 minutes.
Spray the chicken generously with the cooking spray and place them in the 400F preheated oven.
Bake until golden brown—about 35 to 40 minutes or until the internal temperature reaches 165F. Flip the chicken over halfway through the baking process and spray them with some cooking spray.
Once the chicken pieces are done, remove them from the oven and let them rest for 3-5 minutes before serving.