Here’s the secret, and it’s almost too easy. You need cornstarch. Yes, that box hiding behind the salt shaker. It’s the hero of this story.
Cornstarch has zero protein. When you mix it with all-purpose flour, it dilutes the gluten-forming potential. You’re basically tricking the flour into acting like its fancy cousin.
The rule is simple: for every 1 cup of cake flour called for, use 1 cup of all-purpose flour minus 2 tablespoons. Then add 2 tablespoons of cornstarch. That’s it. You’ve just created Franken-flour.
Let’s Break That Down (Slowly, Like a Good Friend)
Grab a measuring cup. Scoop out exactly 1 cup of all-purpose flour. Now, take out two level tablespoons. Put those flour spoonfuls back in the bag.
Now, take your 2 tablespoons of cornstarch and dump them into that slightly-less-than-a-cup of flour. Whisk it like you mean it. Sift it twice if you’re feeling fancy.
The sifting is actually key. You want the cornstarch to be so cozy with the flour they become one soul. No lumps allowed. Lumps are the enemy of even baking.
