The first step in frosting your cake is to add a foundation coating of icing. Because the mix rises as it bakes, the top of each layer of cake will be a little rounded. For a basic two-layer cake, you’re going to frost the rounded top of the bottom layer, then set the top layer rounded-side down on top of the bottom layer. That will leave you with a flat cake top to decorate.
When you have your layers stacked, begin spreading your frosting over the top and sides. Think of this “crumb coating” as a primer layer. It seals in the crumbs and holds the layers of the cake together. Once you have this layer spread evenly around the cake, set the cake aside for a couple of hours to let it dry. Then it’s ready to frost.
Frosting The Cake
To add a smooth coat of frosting around the cake, use a triangle-shaped, metal spatula (they look a lot like a painter’s palette knife). Keep a wide glass of hot water handy – you’ll use it to clean the spatula and to smooth the icing as you frost the cake. Spread frosting a little at a time onto the sides of your layer cake. Dip into the hot water constantly, using it to keep the frosting smooth. Work your way all the way around the cake, then spread the frosting on the top. Don’t be stingy with the frosting – you don’t want any of the cake to show through.
When the outside of the cake looks smooth, let it sit for another couple of hours so the frosting can dry before you start decorating.
For fun shapes on your birthday cakes (or any other kinds of cakes), start with paper cut-out stencils. Simply draw a silhouette of an animal or flower, for example, and cut it out. If you use an extra piece of wallpaper as the material for your cutout, you can wash it when you’re done and use your stencil again and again. If you don’t think you can draw well enough, try cutting out a picture from a coloring book. Lay it over the top of your cake and spread frosting over the cut-out part.
Next, use an icing applicator to outline your shapes. The most versatile way to apply icing is with parchment paper cones you roll yourself. You can use them, fitted with different-sized applicator tips available at cake supply stores, to add details to your pictures. You’ll also use them to write “Happy Birthday” or whatever else you want to say on your cake. Don’t worry about mistakes – as long as the underlying frosting layer is dry enough, you’ll be able to easy lift off any mistakes you make as you go along. But if the frosting is still wet, you’ll lift some of it off too. Experiment with different applicator tips to add flowers, animals, grass – whatever your imagination can come up with.
Making Icing Roses
Icing roses add an elegant touch to birthday cakes, and on wedding cakes they’re indispensable. Use a “nail” to make roses. That’s a tool available at cake supply stores that looks something like an oversized thumbtack. Fit your decorating bag with a round No. 10 or No. 12 icing applicator tip and affix a 2-inch square of wax paper to the top of your nail with a dot of icing. Holding the nail in one hand, turn it as you use your icing applicator to create a dome-shaped base for your rose. Make sure it has a full, round bottom and ease up on your pressure as you lift the tip to form a slightly pointed top.
Switch to a flat, No. 104 decorator tip. Now make the “center bud” on top of your rose base. Start with the wide end of the tip touching the rose base in the middle and the narrow end up and slightly in. Turn the nail as you squeeze a tight ribbon on top. Now, starting near the bottom of the base and holding the decorator tip so that the edge is horizontal, simultaneously turn the nail as you squeeze out a row of three “petals” around the rose base. Continue with an underlying row of five petals, then a third row of seven petals if you want. When your rose is round and full, carefully use a flat-edge palette knife to lift it off the nail and lay it to the top of your cake, pulling the wax paper square out from underneath it.
For an interesting pink gradation, add a little red frosting to the inside of the icing applicator bag before you fill it with white icing. You can play around with yellow, pink, red and white icing and practice until you have roses you’re happy with. Use a leaf-tip applicator to make green leaves around them once they’re on the cake.