1 tsp. garlic powder
2 1/2 c. buttermilk, divided
1 tsp. celery seed, divided
1/2 tsp. cayenne pepper, plus a pinch, divided
Kosher salt and freshly ground black pepper
4 small chicken drumsticks, skin removed
4 small bone-in chicken thighs, skin removed
1 c. all-purpose flour
4 c. cornflakes cereal, crushed
Sliced dill pickles, for serving
Preheat oven to 425°F. Combine garlic powder, 1 1/2 cups buttermilk, and 1/2 teaspoon each celery seed, cayenne, and salt in a bowl. Add chicken and marinate in the refrigerator for 30 minutes.
Fit a rack over a large rimmed baking sheet lined with heavy-duty foil. Combine flour, a pinch of cayenne, and the remaining 1/2 teaspoon celery seed in a bowl. Season with salt and pepper. Place remaining 1 cup buttermilk in a second bowl; season with salt and pepper. Place cornflakes in a third bowl.
Remove chicken from marinade, letting excess drip off; discard marinade. Coat chicken with flour mixture, dip in buttermilk, then coat with cornflakes, pressing gently to help adhere. Arrange chicken on a prepared baking sheet. Bake until cooked through, 25 to 27 minutes. Serve with pickles alongside.