Before starting this Opera Cake recipe, make sure you have organised all the necessary ingredients. The two sheets of Joconde biscuit have been cooked beforehand, using two Flexipan® Entremets mats (33.5 x 33.5cm). When the Joconde sheets are cold, remove them gently from the mat onto your worktop surface. Place a square tart ring (20 x 20cm) in one corner of the Joconde biscuit. Use the square ring as a guide and cut the biscuit to the same dimensions. ...