In a large shallow bowl, whisk the sugar, cinnamon, and nutmeg together. Set aside.
¾ cup granulated sugar, 2 teaspoons ground cinnamon, ¼ teaspoon ground nutmeg
Preheat air fryer to 350°F.
While the air fryer preheats, separate the biscuit dough into individual biscuits and place them onto a clean work surface. Roll each biscuit out to 1-inch thick. Use a biscuit cutter or donut cutter to cut a 1-inch hole out of the center of each biscuit.
12 ounces refrigerated jumbo biscuits
Spray the bottom of the air fryer with nonstick spray.
Place the biscuit donuts in a single layer, with space between each, in the air fryer basket. If there isn’t room for all of the donuts, cook them in batches.
Cook the donuts for 4-5 minutes, or until golden brown all over.
While the donuts cook, place the butter into a shallow microwave-safe bowl. Microwave in 30-second increments until melted.
4 tablespoons salted butter
Remove the donuts from the air fryer. Immediately dip each donut (both sides) into the melted butter and coat completely with the cinnamon sugar mixture. Serve warm.