Occasionally a recipe suggests that you “torte” the layers of a cake. This is a technique where you take one cake layer and cut it horizontally into two or more layers. Always use a thin, sharp knife. (We like a long hollow edge slicing knife as described in How to Level Your Cake Layers). If it is longer than the width of your cake, it will be easier to perform this task.
First, the freehand approach. Place your whole cake layer on a cardboard of the same size, then place on your turntable, if you have one. This tool will facilitate the process. Bring your eye down to cake level so that you can easily assess the path of the knife as you cut. Cut horizontally into as many cake layers as you need – cutting in half, thirds or quarters, for instance. If you have spare cardboards, place each newly cut layer on one; this will protect them as you move them around and re-assemble your cake.
You could try and do this by eye, but it can be difficult. A more exacting technique is to put the cake on a cardboard round and cut a small vertical line into the cake’s side, from top to bottom—just deep enough to see (you’ll be using this later to line the split layers back up). Hold a ruler vertically against the cake, placing the ruler on the top edge of the cardboard to get true measurements of the actual cake.
Make small holes with toothpicks at the level(s) where you want to cut at intervals all the way around the circumference of the cake moving the ruler around the cake as you go to help you mark properly. Place your cake in the center of your turntable and place your knife horizontally against one of the holes.
Start gently cutting into the cake, spinning the turntable slowly, cutting all the while and always making sure that the blade is level (horizontal) and hitting the right spots. Continue until the cake is cut evenly all the way through. Slide this layer onto another same-size cardboard and set aside. Continue if you are cutting more layers.
Now you are ready to fill and frost your cake. Line up those initial vertical cuts after you have applied your filling to make sure you are putting your cake layers back together correctly.