One inch = 2.54 cm, which is a cake with a diameter of 15.24 cm. 6 inches (15.24cm) refers to the blank of the cake, excluding the decoration such as cream.
As far as birthday cake is concerned, a 6-inch cake is smaller. A 6-inch cake is only about 15 cm in diameter, which is enough for 2-3 people. So 6-inch cakes often appear on children's birthdays, so they won't be wasted.
Cakes are usually made in the oven. Cake is mainly made of eggs, sugar and flour. Milk, fruit juice, milk powder, fragrant powder, salad oil, water, shortening and baking powder are auxiliary materials. After stirring, concocting and baking, sponge-like snacks are made.