Combine the egg whites with the powdered sugar and beat them with a mixer until stiff peaks form.
Use a spatula to carefully transfer the egg white mixture into a pastry bag, then place it in the refrigerator for 10 minutes.
Line a baking sheet with a silicone mat and pipe the meringue onto it.
Place the baking tray in the oven and bake the dessert for 40-50 minutes until done. Leave the meringue in the oven until it cools completely.