Chill cake until nearly frozen. Place on a thin cake board, fixing it in position with a few dabs of decorator’s buttercream icing. If cake is layered, sandwich layers together by piping icing over top of bottom layer and placing another layer on top. Repeat as necessary. Fill a large piping bag, fitted with a quick-ice tip, with more icing. Gently squeezing the bag, pipe strips of icing over the top and sides of cake to completely cover it. For a smooth finish, spread icing with a spatula, holding it flat against the top and sides of cake, while turning the cake, preferably on a turntable cake stand.
Dust work surface lightly with confectioner’s sugar and spread out fondant on it. Make a well in center, add a few drops of gel color (you can also use airbrush color sparingly), and knead until color is blended in. Repeat for a darker color, adding just a little color at a time to reach desired shade. If fondant becomes sticky, knead in a little confectioner’s sugar. Wrap fully in plastic wrap and store in airtight container.
Knead fondant until pliable. Place on work surface, dusted with either confectioner’s sugar or corn starch (corn starch is best for humid climates, as it dries out fondant more quickly). Flatten fondant with hands, then roll out with a rolling pin to about 1/4 in. (5 mm) thick. Lift fondant occasionally to ensure it is not sticking to surface (dust work surface with more sugar or corn starch if needed).
If you are working with a small amount of rolled-out fondant, you can use your hands to lift and drape it over the iced cake. Note that the icing on the cake should still be moist to the touch at this point or the fondant will not adhere. If the icing has dried out, either airbrush a mist of water or vodka over the surface of the iced cake, or lightly brush the icing with water before applying the fondant. When working with a large piece of fondant, it is best to roll it loosely around your rolling pin and unfurl it from the rolling pin onto the cake. Once the fondant is on the cake, quickly smooth the surface, using either your hands or icing smoothers. Use a sharp knife to trim away any excess fondant.
Trace around the template with a pencil onto baking parchment. Cut out with scissors. Using dabs of buttercream icing, fix the cutout shape of parchment in position on the chilled cake. Cut around it, taking care to use a straight up and down motion to achieve a clean, vertical edge. Pull away excess cake and freeze it; you never know when you’ll need a bit more cake. Remove the baking parchment shape.
Tall cakes need extra support. Cut cake into 4-6 in. (10-15 cm) high layers. Fix bottom layer to cake board with a few dabs of buttercream icing. Spread icing over top surface, dust with confectioner’s sugar, and insert a few 1/8 in. (3 mm) dowels, cut to length, into the cake. Place thin piece of cake board, cut to shape, onto iced and doweled surface and stack next layer on top. Repeat until entire cake is stacked, then ice. With a very tall cake, use a wooden cake board and secure a length of 3/8 in. (8 mm) dowel to it—about 2 in. (5 cm) shorter than cake’s full height. Drill pilot hole into the dowel and fix to board with a wood screw. Stack cake as above, with the addition of a hole cut in each layer of cake board to accommodate the length of 3/8 in (8 mm) dowel.
Cut chilled cake into layers and stack, using buttercream icing, as project requires. With a sharp, serrated knife and using a light sawing motion, carve away at cake, a little at a time. Go slowly until you have the desired shape; you can always carve off more later if needed, but it’s difficult to add cake once it is cut away. Using a template or lightly sketching in guide marks into the cake with a small knife may help.
Once your cake is carved and iced, but before you cover it with fondant, you may wish to build up details of features using modeling chocolate. Think of the chocolate as the “clay” for your sculpture. Roll out “ropes” of modeling chocolate and shape them as instructed in the project that you are making, or as you feel is needed. Building features from chocolate is useful when you want to add details that are too delicate to carve directly from the cake itself. Another benefit of modeling chocolate is that it remains firm and maintains its shape under the weight of a fondant covering. Also, fondant adheres readily to modeling chocolate without needing any extra moisture. Once the cake is covered with a layer of fondant, you can use modeling tools to emphasize the details.
A piping bag made from baking parchment is ideal when piping a small amount of icing or when you want to control the precise size of your icing tip. Cut out a triangle from baking parchment. Hold each end of the parchment between your thumb and forefinger, then turn one end over the thumb and forefinger holding the other end to start forming a cone. Point finger inside the cone toward the pointed end, and wrap over the opposite side to complete. Pinch the pointed end together to fix shape. Now fill the cone with icing, gel, or melted chocolate and crumple the top of it to create a bag. Snip off the tip of the pointed end to form a nozzle. This can be as small as you wish, but I advise cutting a smaller tip than you need, as it tends to stretch.
Create a “paint” by mixing approximately one tsp. of luster, pearl, or highlighting dust with a few drops of vodka or lemon extract. Less is more when adding liquid to dusts; you can always add more if the paint is too thick. Stir mixture until fully blended. Brush on in even strokes. Leave to dry.
I prefer to use a double-action internal-mix airbrush that lets you switch colors without constantly changing cups. Use colors specially made for your airbrush, or mix your own from dusts and vodka, making sure they are thin enough to flow through the airbrush needle. Put a few drops of color in the airbrush and pull back the lever to start airflow. Test on paper before spraying cake. When you are happy, spray color onto cake in light, long strokes. Slowly build up light coats of color. Saturating your cake with a heavy coat causes pooling of moisture or pitting. Applying light layers builds up safely to rich, deep tones of color.
Photocopy any lettering or logo for your project and tape the printout onto a light box or a well-lit window. Place a sheet of edible paper over the lighted image and, using light strokes, trace and color image onto edible paper with edible markers. Let dry, then cut out image with scissors. Apply a thin coat of piping gel to the back of cutout image and set in place on the cake. Smooth over with clean hands until fully adhered.
