Towering corkscrew shapes make spiral cakes dynamic alternatives to traditional square or round cakes. Endless possibilities exist when it comes to spiral cakes, depending on the occasion, and the twisting forms inspire bakers to come up with innovative cake themes and decorations. Carve the spiral shape out of several round cakes of any flavor, stacked with generous smears of frosting in-between to hold them together.
Insert one end of a toothpick into the top of the cake stack, somewhere along the edge. Place a second toothpick about 1-inch away from the first, in the direction of the spiral. Continue inserting a line of toothpicks that spiral down the side of the cake. The toothpicks will serve as a guide when carving the spiral shape. Stop inserting toothpicks about half way down the side of the cake.
Orient the blade of a knife at a slight angle, going in the direction of the spiral, and make a 2-inch cut into the cake, just under the first toothpick. Continue scoring the cake, running the blade under and along the path of the toothpicks. Stop cutting at the last toothpick.
Plunge the end of the knife into the top of the cake, 2 inches in from the edge, so the blade intersects the first slice. Continue cutting, running the knife around and 2 inches in from the top edge of the cake. Gradually increase the depth of the cut so it is even with the toothpicks and intersecting the first cut. Start to bring the knife closer and closer to the edge of the cake, tapering in and ending the cut at the last toothpick.
Remove the toothpicks.
Carefully remove the now-severed section from the cake, taking great care to keep it in one piece. Turn the section upside-down. Position the highest point of the removed section where the spiral cut ends half way down the cake. The slant of the top of the removed section will carry the spiral the rest of the way down the cake. Adhere the section to the side of the cake with frosting.