Sugar

We usually think of sugar only as a sweetener, but it actually adds to the cake’s volume, which affects its grain and texture. Creaming the sugar into the fat is not just a way to add this ingredient to the batter. Its granules rub against the fat, creating friction and helping trap air cells in the fat. During baking, sugar caramelizes, coloring the cake’s crust. Since sugar traps moisture, it also contributes to the cake’s freshness.