A roller skate cake can make a birthday party at the skating rink or at home unforgettable. Choose a two-dimensional cake, resembling a skate on its side, if you're a beginner. The more adventurous, advanced baker can assemble a standing, 3-D cake that looks almost indistinguishable from a real skate. Either style can be decorated with buttercream frosting or covered in fondant for a smoother finish.
Start a horizontal roller skate cake with a skate-shaped cake pan or a layered sheet cake. Stack the layers of the cake and freeze it partially before carving to prevent it from crumbling as you cut. Cover the cake with a layer of smooth buttercream frosting or a piece of fondant rolled to about 1/4 inch thick. Pipe on decorative details with frosting or apply fondant cutout decorations by brushing the back of the cutouts with a bit of water. Make shoelaces from thin strands of fondant, rope candy or frosting piped from a round decorating tip. For the wheels, you can employ donuts, wheels shaped from fondant, or small, round pieces of cake covered with buttercream frosting or fondant. Add stitching detail to fondant with a rotary quilting tool or an edible marker; use a fine round tip to pipe stitches with buttercream frosting.
Cakes baked in loaf pans form the shape of a standing roller skate boot. Start with whole loaves at the bottom and use half-loaves at the boot throat. Fine-tune the shape with a serrated knife after layering the cakes in the basic shape. Place the cake on a cake board cut to the exact size as the bottom layer. Decorate the cake with your choice of fondant or buttercream frosting. The wheels can't support the weight of the cake, so rest the cake board on top of wooden or foam blocks cut to roughly half the size of the cake board. Position the wheels under the cake board, making it appear as though the wheels support the cake. Shape a rubber stopper from fondant; insert it at an angle with a toothpick at the front of the cake.