In a microwave-proof bowl melt the butter.
2 tablespoons butter
To the melted butter add Worcestershire Sauce, rosemary, chili powder, mustard powder, and brown sugar. Stir to combine.
2 teaspoons Worcestershire Sauce, 4 tablespoons rosemary, 1 teaspoon chli powder, 1 teaspoon mustard powder, 4 teaspoons brown sugar
Add the cashews to another bowl. Pour the butter mixture over the top.
2 pounds cashews
Stir to coat the nuts with the butter mixture.
Place the nuts in a layer in the air fryer tray. When making a larger batch, half the mixture and make it in 2 separate batches.
Set the air fryer to 300 degrees and cook for 4 minutes. Remove the tray and stir the nuts. Put the tray back and cook for an additional 4 minutes. Repeat one final time.
Take the nuts and spread them on a cookie sheet with parchment paper to cool.
Store in a sealed container for up to 1 week.