Modern cake, especially layer cakes, normally contain a combination of flour, sugar, eggs, and butter or oil, with some varieties also requiring liquid (typically milk or water) and leavening agents (such as yeast or baking powder). Flavorful ingredients like fruit purees, nuts, dried or candied fruit, or extracts are often added, and numerous substitutions for the primary ingredients are possible. Cakes are often filled with fruit preserves or dessert sauces (like pastry cream), iced with buttercream or other icings, and decorated with marzipan, piped borders or candied fruit.Cakes may be classified according to the occasion for which they are intended.
For example, wedding cakes, birthday cakes, cakes for first communion, Christmas cakes, Halloween cakes and Passover plava (a type of sponge cake sometimes made with matzo meal) are all identified primarily according to the celebration they are intended to accompany. The cutting of a wedding cake constitutes a social ceremony in some cultures. The Ancient Roman marriage ritual of confarreatio originated in the sharing of a cake. Particular types of cake may be associated with particular festivals, such as stollen or chocolate log (at Christmas), babka and simnel cake (at Easter), or mooncake. There has been a long tradition of decorating an iced cake at Christmas time; other cakes associated with Christmas include chocolate log and mince pies.
Special cake flour with a high starch-to-gluten ratio is made from fine-textured, soft, low-protein wheat. It is strongly bleached, and compared to all-purpose flour, cake flour tends to result in cakes with a lighter, less dense texture. There ore, it is frequently specified or preferred in cakes meant to be soft, light, and or bright white, such as angel food cake. However, if cake flour is called for, a substitute can be made by replacing a small percentage of all-purpose flour with cornstarch or removing two tablespoons from each cup of all-purpose flour. Some recipes explicitly specify or permit all-purpose flour, notably where a firmer or denser cake texture is desired. Special tools are needed for more complex cake decorating, such as piping bags or syringes, and various piping tips. To use a piping bag or syringe, a piping tip is attached to the bag or syringe using a coupler. The bag or syringe is partially filled with icing which is sometimes colored. Using different piping tips and various techniques, a cake decorator can make many different designs. Basic decorating tips include open star, closed star, basketweave, round, drop flower, leaf, multi, petal, and specialty tips.
Royal icing, marzipan (or a less sweet version, known as almond paste), fondant icing (also known as sugarpaste) and buttercream are used as covering icings and to create decorations. Floral sugarcraft or wired sugar flowers are an important part of cake decoration. Cakes for special occasions, such as wedding cakes, are traditionally rich fruit cakes or occasionally Madeira cakes, that are covered with marzipan and iced using royal icing or sugar-paste. They are finished with piped borders (made with royal icing) and adorned with a piped message, wired sugar flowers, hand-formed fondant flowers, marzipan fruit, piped flowers, or crystallized fruits or flowers such as grapes or violets.