Recipe Instructions:
1/2 cup (120 grams) superfine sugar, plus more for sprinkling
3 eggs
1 cup (120 grams) plain flour, sifted
Powdered sugar, for dusting
Heat oven to 390°F or 200°C.
Beat together the sugar and eggs in a metal bowl set over a bain-marie (double boiler) until the mixture reaches 45°C or 110°F (the mixture should feel like a very warm bath—it takes about 2 to 3 minutes) and is doubled in size and pale, thick and creamy.
Fold in the flour gently, bit by bit, until smooth.
Prepare a cookie tray with baking paper. Fill a piping bag with the batter and pipe cookies roughly 4 inches (10cm) long, 1 inch (2 1/2cm) wide and 1/2 inch (1cm) high. Leave plenty of space between each cookie.
Sprinkle the cookies with some sugar, and then dust over some powdered sugar.
Bake for 6 to 8 minutes, or until the cookies are puffed, dry to the touch, and deep golden in color.
Remove from the oven and let cookies cool completely on baking sheet before removing carefully. Use immediately or, if you want to keep them for later, let the cookies dry out on a wire rack overnight before packing into an airtight container. They will keep this way for 2 weeks.