Preheat the oven to 350F. Line two large baking sheets with parchment paper. Place a large round piping tip in a large piping bag.

Place the egg yolks, ¼ cup sugar, vanilla, and salt in a large mixing bowl. Beat on medium speed until pale and fluffy.

Place the egg whites in a separate bowl. Using clean beaters, beat on high speed until soft peaks form. While beating, add in the remaining ¼ cup sugar a spoonful at a time. Beat until the egg whites are thick and glossy, about 2 more minutes.

Beat the egg yolk mixture again just to remix, then fold the egg whites into the egg yolks in batches until well combined. Sift the flour and cornstarch into the egg mixture and fold until no dry streaks remain. (If the batter is a little lumpy, that’s okay. Don’t over-mix the batter.) Transfer the batter to the prepared piping bag.

Pipe the batter into 4-inch long logs (about 1-inch wide) on the baking sheet, spacing them about 2 inches apart. Dust one sheet generously with powdered sugar.

Bake the dusted sheet for 12 to 15 minutes or until lightly golden and firm to the touch. Let cool completely on the baking sheet. Dust the remaining baking sheet with powdered sugar and bake again as directed. Use or store immediately after they cool, as they will soften the longer they are exposed to air. Ladyfingers can be stored in an airtight container at room temperature for up to 2 weeks.