Step 1

Line a baking sheet with parchment paper.

Step 2

Lay a puff pastry sheet flat on a lightly floured surface. Use a pastry brush to cover the sheet completely with the beaten egg. Fold the sheet into thirds along the creases, like a letter, and place on the prepared baking sheet. Repeat with the remaining 3 sheets of puff pastry. Refrigerate until stiff and completely chilled, about 1 hour.

Step 3

Preheat the air fryer to 350°F (180°C) for 20 minutes. Set a wire rack over a baking sheet.

Step 4

Remove the puff pastry from the refrigerator and use a 3-inch round cutter to cut out 12 rounds, 3 per sheet. Use a 1-inch round cutter to cut out the center of each pastry round. Remove and discard the scraps, or air fry for chef’s snacks.

Step 5

Working in batches, place the donuts in the air fryer, spacing 1 inch apart, and cook until the donuts have puffed completely and are golden brown all over, about 15 minutes. Transfer to the wire rack.

Step 6

Make the icing: In a medium bowl, stir together the frosting and milk until smooth. Transfer the mixture to a small piping bag and cut a hole in the tip. Pipe the icing on the top of the donuts.

Step 7

Enjoy!