Dry the chicken: Pat the chicken thighs very dry with paper towels, including under the skin where you can reach. Dry skin crisps; damp skin steams.

Make the ranch butter: In a small bowl, mash the softened butter with 1 tablespoon of the ranch seasoning until smooth.

Butter under the skin: Gently loosen the skin on each thigh with your fingers, being careful not to tear it, and spread about a teaspoon of the ranch butter underneath, right against the meat. Smooth the skin back over.

Season the outside: Rub the thighs all over with the olive oil, then sprinkle on the remaining 1 tablespoon ranch seasoning, the garlic powder, and pepper, pressing it onto the skin.

Preheat the air fryer: Preheat your basket air fryer to 400°F for 3 to 5 minutes.

Air fry: Arrange the thighs skin side up in a single layer with space between them, working in batches if needed. Air fry at 400°F for 18 to 22 minutes, until the skin is golden and crisp and the meat reaches at least 165°F at the bone, ideally 175°F for dark meat. No flip needed if you want the skin fully crisp on top; air fryer models vary, so use the thermometer as your real test.

Rest and serve: Let the thighs rest for 5 minutes so the juices settle back into the meat, then serve.