Why do you use corn starch with cake flour?

Cornstarch is often added to cake flour to create a lighter, softer texture in baked goods. It helps reduce the protein content of the flour, resulting in a more tender crumb, which is ideal for cakes. This combination also aids in achieving a finer, more delicate structure, making the cake less dense and more airy. Additionally, cornstarch can enhance moisture retention, contributing to a longer-lasting freshness.