Preheat the oven to 425°F (use convection or air-fryer setting if available). Line a baking sheet with parchment paper or spray aluminum foil with cooking oil.
Pat the chicken thighs very dry with paper towels to remove excess moisture.
In a mixing bowl combine grated parmesan, baking powder, Italian seasoning, paprika, garlic powder, salt, and black pepper; stir until evenly mixed.
Rub the spice-parmesan mixture evenly over each chicken thigh, coating the skin side well.
Arrange the thighs skin-side up on the prepared baking sheet, leaving a few inches between pieces.
Bake for 30–40 minutes (about 30 minutes with convection); if using boneless thighs start checking at about 25 minutes. The chicken is done when internal temperature reaches 165°F and juices run clear.
Optional: use the pan juices to baste each piece before serving.