Make your own cake flour by using a mixture of all purpose flour (a.p.) and cornstarch. For every 1 cup of cake flour, measure 1 cup of a.p. flour, now subtract 2 tablespoons of a.p. flour, and add 2 tablespoon of cornstarch.
1 cup of cake flour = 1 cup of a.p. flour – 2 tbsp of a.p. flour + 2 tbsp of cornstarch