To cut a round cake, use a clean knife dipped in hot water to cut the cake into equal wedges. For a smooth cut, pull the knife out from the side of the cake, instead of the top. To remove a slice, run a knife or spatula under the cake and lift up, then out, onto a plate. Alternatively, to keep a cut round cake fresh, cut long, thin pieces from the center, and then press the cake back together.
To cut a round cake into 12 smooth, even, wedge-shaped slices, dip a knife into hot water and slice the cake into quarters, and then thirds, wiping the knife clean with a towel after every cut. Remove your knife by sliding it away from the center of the cake to the perimeter, instead of lifting it up. If cutting a round cheesecake, use cheese wire or dental floss for similar results.
Another method of cutting a round cake is to remove thin slices from the middle, pressing the cake back together after each slice to keep the inside fresh over several days. Use a rubber band to help keep the slices pressed together, and alternate cuts each day to ensure that the inside of the cake is never exposed to the air.