Measure the Flour: Start with 1 cup of all-purpose flour.
Remove Excess Flour: Scoop out 2 tablespoons of flour and return it to your flour bag.
Add Cornstarch: Replace the 2 tablespoons of flour with 2 tablespoons of cornstarch.
Sift Thoroughly: Sift the mixture together at least 4-5 times to evenly distribute the cornstarch and aerate the flour. This step is essential for a light, airy texture.
Use Immediately or Store: Use the homemade cake flour in your recipe or store it in an airtight container for up to 3 months.