Butter cream

Butter cream or buttercream or mock cream is a type of icing used in cakes, as a coating, and as decoration. In its simplest form, it is made by creaming butter with icing sugar, though other fats can be used, such as margarine or even avocado. Colourings and flavorings are often added, such as cocoa powder or vanilla extract.
A notable use of buttercream is in butterfly cakes, though it is popular as a topping for many other forms of Victoria sponge.