How to Slice Cakes and Layer Cakes Cleanly

The knife is usually what damages the cake. A cold knife sticks to the frosting and drags it along as you pull the knife away; a little more frosting builds up on the blade with each cut and smears the face of the next slice. With cake, the problem is crumbs: a dull or short knife moves as if it is crushing the cake rather than cutting it, and the edges crumble. The solution to these two problems is the same: use a long, thin, sharp knife at the right temperature and keep it clean after each cut. A thick, short knife like a bread knife is the worst choice for this job.

For layer cakes, dip the knife in hot water and dry it immediately with a cloth. The warm blade moves through the frosting and ganache by melting them slightly, leaving a smooth, shiny cut surface. Drying the blade is essential; water dripping from it leaves marks on the frosting. Wipe the knife after every cut and reheat it if needed. This may seem like a lot of work, but if you do not repeat it for every slice, the blade will be coated with frosting after the first two slices and the benefit will be lost. Fill a long container with hot water so the entire blade can be submerged.

The motion depends on the type of cake. For soft desserts such as layer cake and cheesecake, do not saw the knife back and forth; press straight down in one stroke and pull it back along the same path. For cake, sponge cake, and dry pastries, use a light sawing motion with a serrated knife; pressing down will collapse the cake’s air pockets. To make even slices, first score light guide lines on the surface with the tip of the knife, then follow those lines as you cut. Start the lines at the center of the cake and extend them outward like the face of a clock.

Temperature matters at least as much as the knife. Take a layer cake out of the refrigerator just before cutting; frosting that warms up softens and slides under the knife. Cake, by contrast, should not be cut as soon as it comes out of the oven. The inside of a hot cake still holds steam, and its starch has not set; cut at that stage and the slice will be sticky and crumbly. Cut the cake only after it has cooled completely. If you want to serve it warm, cut it first and then reheat it. For ice cream cakes, reverse the order: take the cake out of the freezer and let it sit for a few minutes before cutting, because a rock-hard frozen layer cannot be cut cleanly with a knife.

The first slice is always the hardest because there is no space around it to maneuver. After making two cuts, slide a thin cake server under the slice all the way to the base and lift it on the server; a slice lifted with a knife will tip over. Place the slice on its side so the layers are visible. The next slices come out easily through the space opened by the first slice. Do not leave the cut face of the remaining cake exposed; cover it after serving. Wipe crumbs from the edge of the plate with a paper towel, and serve the next slice on a clean plate.