How does the creaming method make rich cakes?

The creaming method is specifically utilized for producing rich cakes, defined as those where the proportion of fat to flour is at least half by weight.1

In this process, the fat and sugar are creamed well together, followed by the addition of beaten eggs. Finally, sifted flour and salt—along with any necessary leavening agents—are carefully folded into the mixture, often followed by liquids or dried fruits. By thoroughly creaming the fat and sugar, bakers create a stable base that supports the structure of these rich, high-fat mixtures, ensuring a consistent texture despite the high fat content.1