Opera cake – classic recipe

Instructions

1. Start by making the Joconde Biscuits sheets. Find the recipe here but increasing ingredients with 50%. Bake 2 sheets in tray with size 32x20 cm. When the Joconde sheets are cold, remove them gently from the baking paper and 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 or use a circle spring form 30 cm to cut for a circle cake. The biscuit should perfectly line the inside of the mould. Make sure you cut along the inner rim of the square/circle. Set aside. Cut the second biscuit the same way and you will have the third layer of the rest of the biscuits by gathering the pieces together in order to have another square. Even though this second square is composed of two pieces of biscuit, this will not make any difference once the Opera cake is assembled.
2. Melt the chocolate couverture for the coating on bain-marie. Using a brush, spread the melted chocolate on the surface of the first biscuit. Apply a very thin layer of chocolate. This will create a hard shell on the biscuit to make it resistant to moisture. Refrigerate the biscuit for 10 minutes to allow the chocolate to set.
3. Prepare the chocolate ganache: In a saucepan, bring the liquid cream to the boil. As soon as it boils, remove the pan from the heat then add the dark chocolate dark chocolate cut into pieces. Mix well with a whisk until a homogeneous mixture is obtained. Incorporate the butter previously cut into pieces. Place the ganache in the fridge for 10 min to cool and then set aside at room temperature.
4. Prepare the butter cream: Place the sugar in a saucepan. Add a little water. Make sure you do not add too much water: use just enough to humidify the sugar (100 ml should be enough). Bring to a boil and cook until the temperature reaches 121°C. Use a digital thermometer – it is highly recommended. If you don't have one, dip a fork in the boiling sugar. If you see strings forming when you take the fork out, that means the sugar is ready. Place the egg yolks in the stand mixer. Store the leftover egg whites in the fridge or in the freezer and for another recipe in the future. When the sugar is ready, gradually pour it against the inner side of the bowl to avoid splashes of hot sugar. The mixer is turned on low speed. The egg yolks should be at room temperature. Once the sugar is completely combined with the egg yolks, continue beating on high speed until the mixture has cooled down completely and then gradually incorporate the softened butter, cut into cubes. Continue beating until you obtain a smooth and homogeneous cream. At this stage, you can add the coffee flavour if you like.
5. Sugar syrup: Pour the water into a saucepan. Add sugar. Bring the mixture to a boil. Stop cooking as soon as the sugar is completely melted.
6. Assembling the cake: Take the chocolate-coated biscuit square out of the fridge. Place it on your kitchen worktop. The chocolate should now be set. Flip the biscuit so the chocolate-coated side is facing down. Place the square/ circle ring around the biscuit. This is the same square/circle as the one used to cut the biscuit at the start.
7. Using a pastry brush, steep the Joconde layer with syrup. Add some coffee flavour to syrup if you like. When the whole surface has been moistened with syrup, add one and a half rubber spatula of the butter cream. The consistency should be smooth and creamy. Spread the cream into a thin layer, to a thickness of 3 to 4 mm. Make sure you do not coat the sides of the ring with coffee cream, otherwise you won't see the distinct layers of the cake when you release it from the ring.
8. Take the square of biscuit that is made of two pieces. This time, put the biscuit on your worktop surface to brush with syrup, as you're going to apply syrup on both sides. Gently flip and arrange the biscuit over the butter cream, soaked side is facing down. Brush some syrup over the other side of the biscuit.24 Use the chocolate ganache as a fourth layer. Using a rubber spatula, add two scoops of chocolate ganache. Spread into a thin layer. Again, try not to coat the sides of the ring.
9. On your worktop surface, brush one side of the last biscuit square with syrup. Arrange the biscuit on top of the chocolate ganache, soaked side facing down. Brush the remaining syrup over the other side of the biscuit. Spread another layer of butter cream, to a thickness of 3- or 4-mm.32 Even the surface with spatula. Cover with a cling film. Refrigerated for at least 2 hours before finishing with chocolate icing.
10. Up to this stage, this recipe can be prepared the day before. If you wish to make it several days in advance, you will need to store it in the freezer. On the day, all you will need to do is the icing.
11. For the chocolate icing: Melt the dark chocolate over a bain-marie. When melted completely and add the grapeseed oil.
12. Take the cake out of the fridge. If you stored the cake in the freezer, remove it several hours before and let it defrost slowly in the fridge. When you're ready for the icing operation, the cake should be very cold, but not frozen. Remove the ring and pour the chocolate icing (at room temperature) on top of the cold butter cream. The thickness should not exceed 2- or 3-mm.
13. Even the surface, using a large spatula that allows you to slide across the cake in one motion.
14. If necessary, pour some more icing and even the surface.
15. If you would like to trim the edges of the cake, return the cake to the fridge for a while to allow the icing to set. It should take about 10 minutes for the icing to set.
16. Dip the blade of a knife in hot water, then trim the edges to about 0.5cm in a sharp motion. This will ensure the cake has perfectly neat sides.
17. Finally, apply a small piece of mint leaf in the centre.
18. Enjoy this classic French dessert!

• Servings : 16
• Ready in : 350 Minutes
• Course : Dessert and Snacks
• Recipe Type : beef, Christmas Recipes, Dessert, Easter Recipes, recipes for spring, recipes for summer, recipes for winter
• Ingredient : Almond flour, Butter, Dark chocolate, Double cream, Egg yolks, Grape seed oil, Mint leaves, Strong black coffee, Sugar