How to Prepare Cake Flour with Cornstarch for Velvety Crumb

Instructions:

1. Fluff the all-purpose flour with a spoon and gently spoon it into a 1-cup measuring cup until overflowing. Level it off with the flat edge of a knife.
2. Remove exactly 2 tablespoons of the measured all-purpose flour and return it to the flour container.
3. Add 2 tablespoons of cornstarch into the measuring cup to replace the removed flour.
4. Transfer the mixture into a fine-mesh sieve set over a large mixing bowl.
5. Sift the mixture through the sieve. Repeat the sifting process four more times (five times total) to ensure mechanical aeration and even distribution of the starch.