Prepare melted butter and cut parchment paper in advance.

Mix eggs, sugar, and salt lightly in a bowl.

Warm the mixture gently over a water bath until slightly warm.

Whip the warmed egg mixture until it turns ivory-colored and fluffy.

Sift the all-purpose flour and gently fold it into the mixture.

Mix a small portion of the batter with melted butter, then fold it back into the main batter.

Tap the bowl three times to remove air bubbles.

Bake in a preheated oven at 180°C for 20–30 minutes.