Why You Bother

• A well-made cake is tasty in its own right. There's no reason it can't be enjoyed all on its own, without the fuss and bother of frosting it. Still, frosting brings a lot to the party. It makes your cakes look more appealing, even if you don't have much in the way of cake-decorating skills. It also adds sweetness, richness and moisture to each mouthful, and those are all good things. From the practical viewpoint, your frosting also provides the cake with an airtight seal over its exposed surfaces. That helps keep it fresh and moist, just as effectively as plastic wrap.

Basic Frostings

• The simplest frostings include cream cheese icing and basic buttercream. They're made by beating cream cheese or butter -- or another fat, such as margarine or shortening -- together with powdered confectioner's sugar and flavorings. Most include a hint of vanilla, though other flavorings, such as almond extract, chocolate or lemon, can be added if they complement the cake. These are relatively dense, and they work well with cakes that have a correspondingly firm texture. For example cream cheese icing is often paired with rich carrot cake, while most standard butter cake recipes will stand up to simple buttercream. These frostings are too dense for light and delicate cakes, which tend to tear when the icing is spread.

Lighter Cakes and Frostings

• The skilled baker's arsenal includes a number of lighter frostings for use with extra-delicate cakes, such as angel's food cake or chiffon cake. One is boiled icing, which combines whipped egg whites with hot sugar syrup to make a light, fluffy marshmallowy frosting. Essentially a cooked and sweetened meringue, it glides easily onto the lightest of cakes. Richer Italian or Swiss buttercream is made in a similar fashion, but takes the extra step of beating softened butter into the meringue. These are also light enough for chiffon cakes, and are often used on the sweet and delicate "high ratio" cakes made at most professional bakeries.

Lightening What You've Got

• If you don't have the skills or the time to make a sophisticated whipped buttercream, it's possible to lighten the icing you already have. Simple buttercream or cream cheese icing can be softened and lightened by whipping it in a stand mixer for several minutes. If it's still too heavy for your cake, gently fold in a small portion of whipped cream or stiffly beaten pasteurized egg whites. The airy additions will soften and lighten the icing, making it more spreadable and better suited to a light cake. You can do the same with prepared commercial frosting, if that's all you have available.