Shape these cookies using a fortune cookie stencil.
Preheat oven to 400 degrees. Line a baking sheet with a nonstick baking mat; set aside.
In the bowl of an electric mixer fitted with the whisk attachment, beat egg whites and sugar on medium speed for 30 seconds. Add flour and salt and beat until combined. Add butter, heavy cream, and almond extract and beat until combined, about 30 seconds.
Place a 5-inch round plastic template on prepared baking sheet; spread batter to fill. Repeat process once (two cookies per baking sheet). Transfer to oven and bake until edges turn golden brown, 6 to 7 minutes.
Transfer baking sheet to a heat-resistant surface. Working as quickly as possible, slide an offset spatula under one of the cookies. Lift it up, and, using your fingers, fold the cookie in half, pinching the top together to form a loose semicircle (if you are placing a message in the cookie, you should fold it in at this point). Hold the cookie with your index fingers inserted at each open end and slide your thumbs together along the bottom line. Press into the center while bending the two open ends together and down to form the shape of a fortune cookie. This whole process should take about 10 seconds. Once the cookie hardens, which begins to happen almost immediately, you cannot fold it into the shape. Transfer fortune cookies to the cups of a large muffin tin to cool. Repeat process with remaining batter. To avoid wasting batter, try the shaping process with a circle of paper first.