Preheat oven to 400oF (205oC)
Line two baking sheets with parchment paper.
Fit large pipping bag with round pipping tip.
Sift flour, corn starch and pinch of salt. Set aside.
Place egg whites in bowl of stand mixer beat for 1-2 minutes, add 3 tablespoons of granulated sugar. Beat until stiff and glossy.
In another mixing bowl beat egg yolks and remaining sugar until pale in color.
Fold half the egg whites into egg yolk mixture.
Fold in flour, and then add remining egg whites. Be very gentle when folding ingredients together. Stir until ladyfinger butter is completely combined but do not overdo it.
Transfer mixture into pipping bag. Pipe on prepared baking sheet 4” lines, leaving 2” of space between sponge cookies.
Bake the lady finger for 10-15 minutes or until the edges are golden brown.