Combine chicken legs, thighs, and buttermilk in a resealable plastic bag. Marinate for 1 to 1½ hours in the refrigerator.
Mix the flour, spices, and salt in a bowl.
Remove chicken legs and thighs from the buttermilk and dredge in the flour, making sure the chicken is completely covered, then place the on a cooling rack fitted over a sheet tray at room temperature for 15 minutes.
Place the crisper plate into the Cosori Smart Air Fryer basket, then place the chicken onto the crisper plate. Spray the chicken generously on all sides with oil spray.
Select the Chicken function, adjust time to 17 minutes, then press Start/Pause.
Remove the chicken and let cool for 5 minutes, then serve.
