Homemade Cake Flour

I'd like to make my own cake flour. What is the ratio of cornstarch to flour? —J.M.Wyalusing, Pennsylvania

For every cup of cake flour, use 1 cup minus 2 tablespoons bleached all-purpose flour plus 2 tablespoons cornstarch. Keep in mind that cake flour has properties different from all-purpose flour, so the result may not be the same.