Prep: In a microwave-safe bowl, gently melt butter until just starting to liquify, about 10-20 seconds. Mix in both sugars until well combined. Add egg and vanilla, beating for 30 seconds until smooth.

Mix: Incorporate remaining dry ingredients, stirring until dough comes together.

Chill: For best results, refrigerate dough 30 minutes to overnight (optional).

Shape: Line air fryer basket with parchment. Form 2-tbsp dough balls and place 1.5 inches apart in basket. Fit 2-4 cookies depending on air fryer size.

Bake: Air fry at 325°F / 163°C for 5-7 minutes until golden brown. Let rest in basket 2-3 minutes before removing.