Combine all the spice mix ingredients in a small bowl and mix well. Sprinkle 3 tablespoons of the mix over the chicken legs and rub it in so that the legs are evenly coated.

(Optional) Use your finger to separate the chicken skin from the thigh meat, making sure the edges stay attached. Rub some dry spices under the skin. This step helps the skin to crisp up even more and makes the meat more flavorful.

Let the rubbed legs rest, uncovered, in the refrigerator for 30 minutes to an hour, or 15 to 20 minutes at room temperature.

Combine the dry coating ingredients and the 1 remaining tablespoon of the spice mix in a big shallow plate. Stir to mix well. Add the buttermilk to another low, shallow dish.

Preheat the oven to 400°F (200°C). Line a baking tray with foil for easy clean-up and place a baking rack on the tray. Generously spray the rack with cooking oil.

Once the legs are done marinating, prepare your coating station with the plate of chicken legs, the dish of buttermilk next to that, then the dry coat mixing (I also recommend having a spoon to scoop the dry mix over the chicken).

One at a time, hold the tip of the drumstick using one hand, dip the leg into the buttermilk, and flip to coat the other side. Let the excess buttermilk drip off, then place the leg into the dry mix. Scoop the dry mix over the leg and gently press it in, turning and repeating until the leg is coated. Gently shake off any excess coating and lay the leg on the rack, skin side up.

Add the legs to the oven and bake for about 45 minutes in total, until the chicken is crispy and lightly browned. After 10 minutes take the legs out and drizzle them with a small amount of oil and bake for another 20 minutes. Gently flip the chicken to crisp the bottom, for 10 minutes or so. For the last 5 minutes, flip the chicken right-side-up again to finish up. Once done, test the chicken by inserting a thermometer into the thickest part of the thigh and it should read at least 165°F (74°C). Or you can insert a sharp paring knife into the thigh and the juice should run clear. Bake for another few minutes if the chicken is not yet fully cooked.

Once baked, let the chicken cool off for 5 minutes. Serve over steamed rice as a main dish. Enjoy!