Rice Crispy Treats are often used to provide structural support to unusual and three-dimensional cake forms. The combination of melted marshmallow and puffed rice creates a sturdy, edible building material. While they are still warm, the rice crispy treats can be moulded and formed into almost any shape. After the gooey mass has cooled, it can be carved and sculpted into the final shape. Fondant, icing and other decorations typically disguise the rice crispy form as part of the cake.
Lay a silicone baking mat on a flat, stable surface. Set up a clamp lamp with a heat bulb, approximately 45cm (18 inches) away and pointed at the mat.
Spray a thin layer of cooking oil spray onto the silicone mat, spatula and interior of the moulds. Move the hot rice crispy treats from the cooking pot to the silicone mat with the spatula. Gently spread them into an even layer and allow them to cool slightly.
Coat your hands with the cooking oil spray. Tear off a chunk of the rice crispy treat when it has cooled enough to touch. Form the material into a basic shape with your hands or press it into one of the moulds.
Cover the basic rice crispy forms with a sheet of waxed paper. Allow the forms to dry at least 8 hours or overnight.
Carve details into the dried rice crispy treats with a serrated or electric carving knife. Work slowly, removing a little material at a time until you are satisfied with the form. Clean the surface of the carved rice crispy treat with a pastry brush to remove loose puffed rice.
Secure the sculpted rice crispy treats to the cake and cake board with icing. Allow the icing to fully dry before decorating over the rice crispy treat. Rice crispy treats can be made with the flavoured puffed rice varieties for added colour inside the cake.