Make 3 to 4 slits on each drumstick with a knife.
Optional step: To make Indian buttermilk for brining the chicken, simply whisk together 3 to 4 tablespoons of plain yogurt, 1 teaspoon salt, and 2 teaspoons lemon juice with 2 to 3 cups of water in a large enough dish. Add the chicken drumsticks to this mixture making sure all the drumsticks are under the liquid level. Leave them in the refrigerator overnight or for around 10 to 12 hours to brine which will result in a very moist and juicy chicken. After brining, remove the drumsticks from the liquid, and proceed with the next steps.
Mix all the ingredients together for the marination in a bowl.
Apply this marination mixture evenly to the chicken drumsticks and let them marinate for an hour in the refrigerator. ( you can use a large ziplock bag to mix together chicken drumsticks and marination mixture easily)
Preheat the air fryer for 3 mins.
Place the marinated chicken drumsticks into the air fryer without touching each other and leaving enough space between each of them for air circulation. Do not overcrowd your air fryer as this will result in uneven cooking and steaming instead of air frying.
Air fry at 380 F for 20 mins first. Open the air fryer bin at the 10-minute mark, spray or brush oil on the drumsticks, flip them and close the bin to continue cooking.
At 20 minute mark, flip them again, change the temperature to 400 F and cook for the last 5 mins watching closely. Use the meat thermometer to check if the internal temperature reached 165°F to make sure they are cooked thoroughly. If you do not have a meat thermometer then remove a drumstick from the bin and cut it beside the bone and see if it is cooked properly inside before plating them.
Serve them immediately with your preferred choice of side dishes like steamed veggies, fries, soup, salad, or rice. I strongly suggest making them right before serving as they taste best immedietely. You can marinate them beforehand ( even up to 2 to 3 days before ) and air fry them right before eating.