How to Carve a Spiral Cake#2: Then cut into side along toothpicks onside of cake, + you will see your pathway start to emerge 4. Find point on path where it begins to taper + measure how tall cake is at that point. Grab another 1 layer of cake, + cut a piece that is as wide as you measured + as long as you want your pathway to extend + as thick as pathway is. (you’ll be standing it on its side) 5. You should now have something that looks like photo above.