In a large bowl, whisk together the all-purpose flour, baking powder, sugar, kosher salt, and baking soda.

Add the chilled and cubed unsalted butter to the flour mixture.

Use your fingers to break apart the butter pieces and work them into the flour mixture until pea-size pieces form.

Pour the chilled buttermilk over the flour mixture.

Use a rubber spatula to mix together until the ingredients are just combined.

Turn the dough out onto a well-floured surface and pat it into a disk about ½ inch thick.

Using a 2-inch round cutter, cut out 16 biscuits from the dough.

Place half of the biscuits in a single layer in the air fryer basket, ensuring their edges just touch.

Cook at 325°F (163°C) until the biscuits are golden brown and fluffy, about 18 minutes.

Serve the biscuits hot.

Cook the remaining biscuits or freeze for up to 1 month.