Mix the dry ingredients: In a large bowl, combine the Rice Chex, Corn Chex, Wheat Chex, pretzels, cheese crackers, and nuts. Gently toss to distribute everything evenly.

Make the seasoning butter: In a small bowl or measuring cup, whisk together the melted butter, Worcestershire sauce, garlic powder, onion powder, seasoned salt, smoked paprika, and cayenne if using.

Coat the mix: Drizzle half the seasoned butter over the cereal mix. Toss well with a spatula, then add the remaining butter and toss again until every piece looks lightly coated. Don’t rush this step—even coating = even flavor.

Preheat the air fryer: Set the air fryer to 300°F (150°C) for 3 minutes. A lower temp prevents scorching.

Cook in batches: Add a single layer of the mix to the air fryer basket. Do not overfill; you want plenty of airflow. Air fry at 300°F for 6–8 minutes, shaking the basket every 2 minutes. Watch closely in the last couple minutes to avoid burning.

Cool on a sheet pan: Transfer the cooked mix to a large baking sheet to cool and crisp up. Repeat with remaining batches.

Taste and adjust: Once cool, taste and sprinkle with a little extra seasoned salt if needed. Toss to distribute.