Preheat oven to 350 degrees Fahrenheit. Line and grease a baking sheet.

In a medium bowl, whisk egg whites until just foamy. Whisk in sugar, margarine, and almond extract. Whisk in flour and cornstarch until flour is dissolved and batter has an even consistency, about 30 seconds. (Do not overwhisk.)

Allow to sit for 20 minutes at room temperature.

Meanwhile, print fortune messages to place inside each cookie.

Whisk two tablespoons water into the batter and check the consistency—it should be loose and spreadable like crepe batter. If it’s sticky and difficult to spread, add one to two tablespoons water.

Spoon one tablespoon batter onto the baking sheet. Using the back of a spoon, spread batter evenly to create two thin three-inch circles. (Only bake two cookies at a time because you’ll want to assemble and shape them quickly while they’re warm.)

Bake cookies until golden brown around the edges, 10–13 minutes. Watch them, as they can easily overbake.

Working quickly, using a spatula, gently release edges of one cookie and place a fortune in the middle. Fold in half to make a half-moon shape, then gently press edges together with the tip of the spatula. Fold cookie over the rim of a mug, edge-side up, to create a fortune cookie shape. Place in a muffin tin to keep the shape and allow to cool.

Repeat with remaining batter.