Preheat the air fryer to 375F for 5 minutes while you prepare the cookie dough.
In a medium bowl, whisk together the butter and brown sugar until well combined.
Next add the egg yolk and vanilla. Whisk to combine.
Add the flour and baking soda. Mix just until no large lumps of flour remain.
Finally, add the chocolate chunks and stir until they are fully incorporated.
Line the air fryer basket with parchment paper and use a 1.5 tablespoon scoop to portion out 6 cookie dough balls. Place them at least 2” apart in the air fryer basket– don’t overcrowd the air fryer basket.
Cook for 6-8 minutes, or until the cookies are golden brown and crisp.
Remove the cookies to a wire rack to cool and repeat steps 6-7 with any remaining cookie dough.