Dry the chicken well. Make sure to pat the drumsticks dry really well before seasoning – even a little moisture can steal that perfect crunch.
Use baking powder, not baking soda. They may look similar, but baking soda will spoil the flavor with a bitter, metallic aftertaste. Baking powder, on the other hand, gently dries the skin and makes it beautifully crisp.
Don’t overcrowd the rack. Give chicken drumsticks breathing room so the hot air can flow and brown every side evenly.