Preheat the air fryer to 325 degrees F, air fryer setting.
In Bowl One: Whisk together the coconut flour, stevia, xanthan gum, and baking powder.
In Bowl two (microwavable): Add your mozzarella to a bowl and place it in the microwave. Microwave for about 1 minute while checking on it every 20-30 seconds. Cheese should be well melted but not burnt or dried out.
Add the mozzarella and the egg to the coconut flour mixture. Combine well and form into a ball of dough. Optional: To make the dough easier to handle, freeze for 30 minutes.
Knead the ball of dough if necessary and roll it out between two sheets of parchment paper. Try to form as much of a circle of dough as possible.
Cut the dough into 6-8 pieces with a pizza cutter or knife. When sliced, it should resemble a sliced pizza.
Roll from the longer, wider outer edge to the pointed corner. Pinch the dough where needed to seal but be careful not to pinch too much. Bend the corners for a croissant shape. Repeat with other slices.
Brush or spoon butter onto the croissants.
Air fry 5-8 minutes at 325F. Add time in two-minute increments if not yet golden brown depending on your air fryer.
Cool slightly before serving.
Plate, serve, and enjoy!