No tropical-themed cake is complete without some sort of lush, candy-based foliage decoration. Adding a few standing palm trees to your tropical cake will lend a striking 3-D element to the ornamentation. These sorts of clever, eye-catching cake embellishments may seem like they'd not only be excessively complicated to make, but would also require hard-to-find baking tools to assemble. However, aside from an inexpensive icing bag, fondant and green food colouring, you most likely already have all the tools you need in your kitchen.
Don your plastic food-service gloves. Open a package of fondant, and work it into a ball until it's elastic and supple.
Tint your fondant ball green by adding green food-grade colouring to the ball with a toothpick. Apply small specks of colouring all over the fondant ball. Apply 1 tsp of colouring for every 284gr. of fondant. Blend the colouring into the fondant by kneading it until the green colour is uniform.
Roll out and flatten the fondant with a rolling pin on waxed paper until it's 1/8 inch thick. Cut out several leaf shapes. Make narrow cuts in the sides of your fondant leaf shapes to give them the palm treelike appearance of separate leaves within leaves.
Sprinkle your rolling pin with cornstarch. Drape the fondant leaves over the rolling pin to dry in a slight curve.
Tint a batch of hard-drying royal icing with the same green colouring you used to tint your fondant palm leaves. Pipe a small mound on a sheet of waxed paper. Insert the ends of 3 or 4 fondant leaves into the royal icing. Support the fondant leaves with balled-up paper towels while the royal icing dries and hardens.
Pipe another small mound of green royal icing on top of the dried mound. Place the ends of another 3 or 4 leaves into the upper royal-icing mound. Gently stuff balled-up paper towels in between the lower and upper fondant leaves to support the upper leaves as they dry.
Pipe a small dollop of the green royal icing on the end of an unsalted pretzel rod. Gently set the bottom of your palm-leaf assemblage onto the end of the pretzel rod. Hold the palm-leaf assemblage in place until the royal icing has dried enough to support the weight of the fondant.
The green food colouring used in your palm-tree leaves may stain skin, teeth and counter tops, but these stains are easily removed with soap and water, toothpaste and bleach, respectively. Hard-drying royal icing can be bought at many larger supermarkets and speciality baking-supply stores, but can just as easily be prepared at home from scratch.