Best Type of Icing

• The peaks and waves you make in buttercream icing can easily lose shape if the cake is stored in a warm environment. For best results, decorate the cake with a crusting buttercream frosting made with vegetable shortening which has a higher melting point than butter. Make a standard buttercream, but substitute at least half of the butter in the recipe for vegetable shortening. Vegetable shortening stays solid at room temperature which helps the icing on the cake to hold shape. Alternatively, try making the rough appearance with royal icing, a type of icing made from powdered sugar and meringue powder that hardens as it dries. This is the same type of icing commonly used on cookies, but must be made to a thick consistency.

Crumb Coat

• A simple crumb coat helps seal in crumbs so you don't disperse them throughout the frosting while making the rough texture. Apply a very thin layer of frosting over all sides of the cake with an icing spatula, making the coat as smooth and even as possible. The spatula will likely pick up a few crumbs as you work, so wipe it clean before scooping it in the clean frosting bowl. Allow the crumb coat to harden and form a crust for about 30 minutes before continuing with the top layer of icing. When the crust forms, spread a thick layer of frosting over all sides of the cake for making the rough texture.

Spoon Technique

• Try the spoon technique for creating rough icing when you want peaks similar to choppy waves in the ocean. A simple small teaspoon works well for creating lots of smaller peaks on the cake, while a large wooden spoon works well if you want a smaller amount of wider peaks. Press the spoon down in the frosting and pick it straight up. The icing sticks to the back of the spoon and lifts up slightly, creating a peak when the icing breaks away from the spoon. Twist the spoon while lifting to give a slight swirl to the frosting peaks. Make the peaks immediately after applying the frosting so it doesn't have time to form a crust.

Spatula Technique

• The spatula technique results in shallow grooves and short ridges in the icing. Press the tip of an offset spatula in the frosting and move it from side to side across the cake. When you get to the opposite side of the cake, bring the tip down and make another pass in the opposite direction across the cake, directly beneath the first pass. An offset spatula has an angled blade so you can press the tip in the frosting without getting frosting on the handle or on your fingers, but it's not the only tool that works for this take. A small teaspoon, butter knife or even a rubber spatula can also be used to make the long, shallow grooves.