Building a layer cake can ... the chilling—it will make building a heck of a lot easier. 1. Split: Use a long, serrated knife to slice the cooled sheet cake in half crosswise to create two ...

Bring to the boil and simmer for 4-5 minutes, or until the syrup has reduced by half. Remove from ... Refrigerate the opera cake for two hours to set the layers and make it easier to trim.