Crack 2 eggs into a clean, oil-free, and dry bowl. Separate the whites and yolks into two bowls. Ensure no yolk mixes with the whites to avoid affecting the whipping process.

Add 3 drops of lemon juice to the egg whites. Lemon juice helps remove any eggy odor and stabilizes the meringue. Begin whipping the whites with a hand mixer, and add 50g granulated sugar in three stages:

First, when coarse bubbles form.

Second, when the foam becomes finer.

Third, when the meringue begins to form streaks.

Whip until soft peaks form, meaning the meringue stands upright when you lift the whisk.

Add one yolk at a time to the whipped whites (in two additions). After each addition, mix gently on low speed until fully combined. Be careful to maintain the airy texture.

Sift 60g cake flour into the mixture. Use a silicone spatula to fold gently from the bottom up until no dry flour remains. Avoid overmixing to prevent developing gluten, which will affect the texture.

Fit a piping bag with a suitable nozzle and fill it with the batter. Pipe the mixture onto a baking tray lined with parchment paper into long, uniform strips. Leave space between each strip to prevent sticking.

Sift 20g icing sugar evenly over the piped batter. This gives the biscuits a slightly crisp, sweet coating. Bake in a preheated oven at 170°C (340°F) for 18 minutes. Keep an eye on them as they bake; they are ready when golden brown.