Preheat a 4-quart air fryer to 390°F for 5 minutes.
Place the cubed butter into an air fryer safe 8x8-inch baking dish. Place the dish into the air fryer to melt the butter, this will only take a minute or two, so keep an eye on it.
Once the butter is melted, take out the baking dish and set aside.
In a medium bowl, mix together the all-purpose flour, granulated sugar, aluminum-free baking powder, and salt.
Pour in 1 3/4 cups buttermilk. Stir until a sticky batter forms. If the batter still seems too dry, add a tad bit more buttermilk until the batter is thick and sticky.
Pour biscuit dough into the baking dish (right on top of the melted butter.) Some of the butter will run over the top of the dough. Tip: I will spray my hand with some nonstick spray to help spread the dough out evenly in the pan.
Cut the dough into 9 squares (as best you can). This will help with cutting later when the biscuits are baked.
Cover the baking dish with foil.
Place into the air fryer and cook for 25 minutes, rotating the baking dish halfway through for even cooking.
Take the foil off and continue to cook the biscuits for 5-8 more minutes until browned and a toothpick inserted into the center comes out clean. You want to make sure that middle biscuit cooks fully since it's the last one to get fully cooked so the time may vary.
Carefully remove the baking dish from the air fryer and cut along the seams you made earlier to separate the biscuits and serve.
Notes
Please refer to my FAQ’s (Frequently Asked Questions) and ingredient list above for other substitutions or for the answers to the most common questions.
Make sure to use the foil to ensure that the biscuits will cook thoroughly without browning too fast.
Because of the nature of the air fryer, they will get a darker brown than the ones made in the oven. So for the folks who like crispy edges or tops, this is perfect!
That middle biscuit is the tricky one to get fully cooked so once you take the foil off, keep an eye on it and make sure that middle one gets done.
I test all recipes in basket air fryers since that is the most commonly owned air fryer in the U.S. and Canada. It is impossible for me to test each recipe in every possible air fryer that is out there these days. You will need to use your own knowledge of your particular air fryer to make adjustments as necessary. Note: I don't think this recipe is compatible with a round basket air fryer.
Your air fryer needs to be a minimum of 4 quarts for this to work. If your air fryer is larger, you may need to adjust the baking time.