1. In a small bowl, mix together soy sauce, oyster sauce, rice vinegar, brown sugar, and cayenne pepper. Set aside.
2. Cut tofu into 1 ½-inch slices and dredge with flour.
3. Preheat Air Fryer to 400 F (200 C).
4. Place coated tofu cubes in the Air Fryer cooking basket. Spray with oil. Cook for about 15 minutes or until crisp and golden brown. Cook in batches if needed.