What must be done to a cake before it can be properly decorated?

To properly decorate a cake, the essential step is to ensure that it has been assembled and iced. This process provides a smooth and stable surface for decoration, which is crucial for achieving the desired aesthetic and for the decorations to adhere properly.

When a cake is assembled, it typically means that any layers have been stacked and positioned correctly, often with filling applied between them. Icing the cake serves multiple purposes: it not only creates a barrier that prevents the cake from drying out but also contributes to a more visually appealing finish. A well-iced cake can hide imperfections and create a base that enhances any additional decorations, such as fondant, buttercream, or edible embellishments.

Chilling the cake or cutting it into layers can be part of the preparation process but are not strictly necessary for the purpose of decorating. For instance, while chilling may help in setting the icing or managing the cake's temperature for easier handling, the main focus before decoration is ensuring the proper assembly and icing have been completed.