The filling of this simple-to-make Swiss roll is subtly laced with Irish cream liqueur to add to the festive spirit. Piped chocolate icing forms the bark – an easy way to turn the roll into a log in an instant. Take care not to knock out the air from your sponge mixture as you fold in the flour – once the sponge is baked, the tiny pockets of air keep the sponge pliable enough to roll without cracking, while retaining a light and fluffy texture.