Begin by preheating your oven to 350°F (175°C). Prepare two large baking trays by lining them with parchment paper. Fit a large piping bag with a round piping tip.

In a large mixing bowl, whisk together the egg yolks, ¼ cup of the sugar, vanilla extract, and salt. Continue beating on medium speed until the mixture becomes pale and creamy.

In a separate clean bowl, whip the egg whites until they form soft peaks. Gradually add the remaining ¼ cup of sugar, one spoonful at a time, while continuing to beat on high speed. Whip until the egg whites turn glossy and thick, which should take around 2 minutes.

Give the egg yolk mixture a quick whisk to re-incorporate, then gently fold the whipped egg whites into the yolk mixture in portions. Once the egg whites are fully integrated, sift the flour and cornstarch over the mixture. Carefully fold until the dry ingredients are just combined, avoiding over-mixing, even if the batter appears slightly lumpy. Transfer the mixture to the prepared piping bag.

Pipe the batter into 4-inch (10cm) logs on the baking sheets, leaving about 2 inches (5cm) of space between each log. Generously dust one of the baking sheets with powdered sugar.

Place the dusted tray in the oven and bake for 12-15 minutes, or until the ladyfingers turn a light golden hue and feel firm to the touch. Allow them to cool completely on the tray. Repeat the process with the second baking sheet, dusting with powdered sugar before baking.

Once cooled, the ladyfingers are ready to be used or stored. For best results, store them in an airtight container at room temperature, where they will stay fresh for up to two weeks. Keep in mind that exposure to air will soften them over time.