You can trim the dome off cake layers with a long serrated knife, but for those of us whose aim isn’t quite so precise, there’s the cake leveler. Resembling a coat hanger, it’s essentially a wire stretched between two supports. To use it, adjust the leveler’s height to agree with the amount you need to remove. Draw the leveler through the cake, using a gentle back-and-forth slicing motion, and then remove the top. Levelers also come in handy if you want to split one cake layer into two (or more) even layers.