How to slice a plain sponge horizontally
A reel of strong thread is the key to success when it comes to cutting cake sponges into neat, professional-looking layers.
1. Take a long serrated knife (a bread knife is perfect) and a reel of thin, strong thread, such as nylon or button thread.
2. Using the knife, score a line half the depth of the sponge around its circumference.
3. Embed a length of thread all the way round the sponge into the groove you’ve created with the knife, making sure you have long enough ends left to cross over and hold firmly.
4. Cross over the ends close to the groove around the cake, then pull gently but firmly in opposite directions so the thread cuts through the sponge. Keep the thread crossed at the same height all the way through. Lift away the top half of the sponge. Voilà.
If you’ve got toothpicks at home, you could also try the method in this video to guide the thread.