Preheat oven to 200 degrees C. Write fortunes on strips of paper about 10cm long and 1cm wide. Generously grease 2 baking trays.
Mix the egg white and vanilla until foamy but not stiff. Sift the flour, salt and sugar and blend into the egg white mixture.
Place teaspoonfuls of the batter at least 10cm apart on one of the prepared baking trays. Tilt the sheet to move the batter into round shapes about 8cm in diameter. Be careful to make batter as round and even as possible. Do not make too many, because the cookies have to be really hot to form them into their final shapes and once they cool it is too late. Start with 2 or 3 to a tray to see how many you can do.
Bake for 5 minutes or until cookie has turned a golden colour around the outer edge of the circle. The centre will remain pale. While one tray is baking, prepare the other.
Remove from oven and quickly move cookie with a wide spatula and place upside down on a wooden board. Quickly place the fortune on the cookie, close to the middle and fold the cookie in half. Place the folded edge across the rim of a measuring cup and pull the pointed edges down, one on the inside of the cup and one on the outside. Place folded cookies into the cups of a muffin tin or egg carton to hold their shape until firm.