Preheat oven to 375F and line two baking sheets with parchment paper.
In a large bowl, place the egg whites and beat until soft peaks form using an electric mixer.
Then, slowly add half of the sugar and beat until stiff peaks form for 4-5 min, set aside.
In another bowl, place egg yolks and the remaining sugar and beat until pale and fluffy.
Gently pour the egg white mixture over the egg yolks.
Using a spatula, gently fold them together.
Add vanilla and sift flour and cornstarch over the egg mixture.
Gently fold everything together until combined, be sure not to overmix.
Transfer the mixture into a piping bag with a ½ inch piping tip.
Pipe ladyfingers ½-inch wide and 3-inches wide onto the baking sheet, being sure to leave space between the cookies.
Sprinkle with powdered sugar and immediately bake for 12-13 min.
Remove from the oven and let them cool completely.
Serve with tea or coffee, or as part of a delicious tiramisu.
