Preheat oven to 350F (175C). Place egg whites in a large, completely clean, dry, and grease-free bowl. Use an electric mixer (or stand mixer) to beat until you have soft peaks¹.

Continue to stir on medium-speed and gradually (1 Tablespoon at a time) add half (½ cup/100g) of the granulated sugar. Continue to beat until you achieve stiff peaks². Set aside.

In a separate bowl combine egg yolks, remaining sugar, vanilla extract, and salt. Beat on medium/high speed until lightened and color and slightly thickened (this will take several minutes and the mixture will slightly increase in volume).

Gently pour the yolk mixture over the egg whites. Sift flour and cornstarch over the mixture and use a spatula to gently fold everything together until completely combined (take care to mix carefully and do not use an electric mixer for this step, you don’t want to deflate your egg whites).

Transfer batter to a pastry bag fitted with a ½” piping tip (I use a Wilton 1A, you could also use a disposable piping bag with the end snipped off for an opening that is ½” wide).

Pipe batter into 4” (10cm) lines, leaving 2” (5cm) of space between cookies.

Sprinkle additional granulated sugar evenly over cookies if desired (alternatively you can dust them with powdered sugar after baking and cooling) then transfer to 350F (175C) oven and bake 15-18 minutes or until cookies are slightly golden.

Allow to cool at least 10 minutes on baking sheet before transferring to wire rack to cool completely.

If using for Tiramisu, let them sit, uncovered at room temperature overnight before using. Otherwise, store in an airtight container for 2-3 days.