One of my favorite cakes! Lenôtre and Dalloyau are fighting over the paternity of this delicious dessert. Two layers of coffee buttercream and one of chocolate ganache, all sandwiched between “joconde” cookies punched with coffee syrup… The cake is not as difficult as it looks, but it does require a bit of equipment. You can make it in a large version like I did for 20 people, or you can reduce the quantities and make it in a removable rim cake pan. There are seven successive layers to put in two centimeters of height…!
It will seem a bit perilous for some, but you have to go for it and there are no major difficulties! If you don’t have the frame to make it, you can divide the ingredients by two, and use a removable rim cake pan… The result will be just as delicious.
Recipe from “L’Opéra” for 20 people (!!):
Mona Lisa cookie:
-300g of whole eggs
-450g of so much almond (250g of almond powder + 250g of powdered sugar)
-30g of powdered sugar
-195g of egg whites
-60g of flour
-45g of melted soft butter
-230g of water
-175g of sugar
-20g of soluble coffee powder
Coffee butter cream:
-115g of semi-skimmed milk
-90g of caster sugar
-90g of egg yolks
-375g of soft butter
-12g of soluble coffee powder
-200g of whole cream
-250g of 55% dark chocolate
-35g of soft butter
-270g of brown icing paste
-75g of 55% chocolate
-60g of neutral oil
Insulation cookie joconde:
-100g of 70% dark chocolate
-10g of oil
Start by preparing the Mona Lisa cookie:
Preheat oven to 210°C.
Put the powdered sugar and almond powder in a blender, let it run for 30 seconds. Sift (as for macaroons!) and weigh 450g of this mixture.
Put the 300g of eggs and the flour in the bowl of a robot.
Beat with the leaf (that’s the K in the kitchenaid or kenwood!) for 6-7 minutes.
Meanwhile, beat the egg whites until stiff. Squeeze them with the 30g of sugar.
After 7 minutes, a creamy mixture is obtained. Add the melted butter. Then add the stiffly beaten egg whites. Mix while lifting the dough to avoid dropping the whites!
Pour 1/3 of the dough onto a 30X40 sheet of parchment paper. Spread with a spatula (an elbow is easier to use!! But a large one…)
Spread as evenly as possible
Transfer to a flared edge plate of the same size (30X40).
Bake each plate for 6 minutes. Do the same with the other two thirds. We obtain 3 Mona Lisa cookies.
Prepare the coffee punch. Put the coffee powder and sugar in a saucepan. Add water and put on low heat.
Bring the mixture to a boil and then turn off the heat.
For the coffee buttercream:
Bring the milk with half the sugar (45g) to a boil.
Put the rest of the sugar with the yolks and mix without whitening.
Add hot milk while whisking.
Poach at 85°C, stirring continuously with a whisk.
Transfer to the bowl of the food processor.
Add the coffee powder. Turn on the whisk until the mixture is room temperature. The cream will take on an extremely smooth consistency.
Change the whisk for the sheet (again!) and add the soft butter little by little.
Let the sheet turn until the cream is perfectly homogeneous.
For the chocolate ganache. Heat the whole cream and pour it over the chopped chocolate (or pastilles like mine!).
Add the soft butter and whisk to combine.
Place the frame on each cookie sheet. Run a knife around the inside of the frame to adjust the size of the cookies.
Take a new sheet of paper on top of a cookie, turn it over and place the plate on top of the paper which is then under the cookie… We always follow? Then pull the paper with the help of the plate. The paper removes itself like a decal.
You will then have to isolate the underside of the opera because otherwise the coffee punch will dissolve the cookie by and will stick the cake which will break up. Melt chocolate and oil in microwave.
Pour the entire amount onto a cookie. In the photo I put the insulation on the bottom of the cookie. I was wrong. Therefore, the top side must be insulated with a single cookie. (the one that will be under the cake).
Spread as thinly as possible. Anyway, if it’s ugly, we won’t see it! It just needs a thin protective layer!
Place this cookie on a baking sheet and leave in the refrigerator or freezer until the chocolate has set.
Take the plate out and turn it upside down on a new paper. Place on the bottom plate of the cake frame.
Place the 2 cm high frame around the cake.
Now you have to punch (pronounced sand!) the cookie with a brush. You have to be generous, almost 120g per cookie.
Then pour 300g of coffee buttercream over the cookie.
Spread as evenly as possible with a squeegee, or even a painters knife for plastering.
Once the cream is perfectly spread, add a cookie in the frame, but upside down. Punch the cookie (so the bottom of the cookie is upside down…) with the coffee punch. Then add 400g of chocolate ganache. Spread in the same way.
Add the last cookie upside down, punch it down and press it down to distribute and flatten it.
Put the rest of the coffee buttercream.
Let stand in a cool place for at least an hour, then carefully run a knife around the edge of the frame.
Fade carefully. The opera is almost ready!
This is the brown icing paste. It’s actually a poor quality chocolate, but perfect for icing this delicious cake!
Put the icing paste, chocolate and oil in a double boiler. Melt.
Mix well and when the mixture falls to 30-35°C, pour it all over the cake.
With a ruler (at least 40cm!), thinly spread the icing layer. You don’t want to spread it too much because the icing will harden quickly and everything can go wrong at this point (this has happened to me before and it’s pretty annoying!).
Let the glaze set, then cut the edges of the cake with a long knife.
Gold leaf can be used but it is not necessary! I had a pack of it for gilding frames and since I never used it, I decided to eat it!!!
Sprinkle with gold leaf and detail as desired. In rectangle…
Or in smaller pieces. You can even cut it into a cute version… Let it sit overnight in the fridge before eating it!