In a large bowl, whisk together the buttermilk, egg, 1 tsp. onion powder, 1 tsp. paprika, 1 tsp. garlic powder, ½ tsp. chili powder, 1 tsp. salt, and 1 tsp. black pepper. Set aside.
Add the chicken drumsticks to the buttermilk mixture and thoroughly coat them by tossing and turning. Then, transfer everything from the bowl into a gallon-sized zipper-lock freezer bag. Refrigerate for at least 4 hours, or overnight, ensuring to flip the bag occasionally to redistribute the contents and evenly coat the chicken.
In a separate large bowl, mix together the flour, 2 tsp. onion powder, 2 tsp. paprika, 1 tsp. garlic powder, ½ tsp. chili powder, 1 tsp. salt, and 1 tsp. black pepper. Set aside.
Take one piece of chicken from the bag, letting excess buttermilk drip off. Place the chicken into the flour mixture and toss it to coat. Toss the chicken until each piece is fully coated, using your hands to press the flour onto the chicken to create a thick layer. Repeat this process, adding chicken pieces one by one until they are all in the bowl.
Heat the oil to 350F and do not fill the pot more than ½ full with oil. Carefully place the coated chicken drumsticks into the hot oil. Fry over medium heat until they turn golden brown and crispy on the outside and are fully cooked inside. Cook your drumsticks until they reach an internal temperature of 165F. Remember to flip the drumsticks between each frying cycle for even cooking. Dark meat takes longer than white meat to cook, with an approximate cooking time of 12-14 minutes.
Remove from heat, drain on a paper towel to remove excess oil, and enjoy a taste of Kentucky!