A luscious and luxurious cake decorated with mounds, swirls and curls of delicious chocolate will make anyone's mouth water. Chocolate can be moulded, curled, folded, piped or swirled into nearly any shape with the right preparation and techniques.
Melt chocolate discs in a double boiler, being careful to keep all water out of the chocolate. If you are going to use more than one colour or type of chocolate, work with the lightest and sweetest first, up to the darkest. This will prevent muddying of the colours later.
Heat semi-sweet chocolate until it reaches 49 degrees C (120F), or until 48 degrees C (118F) for milk chocolate.
Temper the melted chocolate by taking some of it on a pastry knife and working it back and forth on a marble slab until it is thin and shiny. When it reaches 27 degrees C (80F), add more chocolate discs and melt them until the chocolate is again smooth and runny. Pour tempered chocolate into a pastry bag with a small piping tip. Practice piping chocolate on to a waxed paper-lined baking tray by moving the tip back and forth in "v" shapes going horizontally, then cross over with more "v" shapes to make a waffle or trellis pattern. Allow it to harden, then use these to decorate your cake. You can also practice making letters and numbers.
Pipe melted chocolate directly on to a cake using the shell or star tip. Go all the way around the base of the cake first, then all the way around the top. Make leaves by painting melted chocolate on to holly or apple leaves. Place them on a wax paper-lined baking tray. Let them harden, then carefully peel the leaf away.
Cover a cake with white chocolate using a transfer sheet, then place the chocolate leaves around the top. Pour melted chocolate into rose moulds and let them harden. Add food colouring to melted white chocolate, then paint the roses using a new, clean, dry brush. Arrange chocolate roses on top of the cake. Grate a little semi-sweet chocolate over the top of the cake as well.
See the Resources section for more ideas on decorating cakes with chocolate.
Use stainless steel utensils and bowls, because these heat and cool faster.
Work with the lightest-coloured chocolate first, working toward the darkest to avoid muddying your colours.
Use food colouring paste instead of liquid food colouring.
Do not get water in the chocolate. It will turn to the consistency of raw liver.
Do not work with chocolate on humid days.