Beat egg whites, gradually adding sugar until stiff but not dry.
Beat egg yolks, 1 cup confectioner's sugar and vanilla until thick.
Fold yolk mixture unto beaten whites very gently. Fold in flour carefully.
Drop batter from spoon to form "finger shapes" about 2 1/2 inches apart on oiled cookie sheet.
Bake until lightly browned at 350 °F for from 12 to 15 minutes.
Remove from sheet. Roll in 1/2 cup confectioner's sugar.
Keep moist by storing with a slice of bread. Yield: 32 lady fingers.