Opera is one of my favorite cakes, and after trying many versions of the classic one (coffee with chocolate), this time I decided to revisit it and prepare a fruity version: yuzu and hazelnut.
I love associating the tangy yuzu to the hazelnut that brings roundness on the palate to reach the perfect balance. It was very light and fresh, perfect for the summer time.
This cake is made of:
- Joconde sponge cake (punched with yuzu syrup)
- yuzu crémeux
- praliné crunch
Joconde sponge cake
Joconde biscuit is very light and airy sponge cake, made traditionally with almond (but in this version I replaced a portion of almond powder with hazelnut powder). It is perfect not only for Opera cakes, but also for many entremets, to be inserted in the middle of the mousse to bring some texture. It is in general punched with a syrup. You can prepare it in advance, cook it and store it in the refrigerator for 2 to 3 days or freeze it for a maximum of two weeks. When you need it, just bring it back to room temperature (it takes a few minutes)
Joconde sponge cake
Joconde biscuit is very light and airy sponge cake, made traditionally with almond (but in this version I replaced a portion of almond powder with hazelnut powder). It is perfect not only for Opera cakes, but also for many entremets, to be inserted in the middle of the mousse to bring some moist texture, or in the tarts as well. It is in general punched with a syrup. You can prepare it in advance, cook it, wrap it with cling wrap and store it in the refrigerator for 2 to 3 days or freeze it for a maximum of two weeks. When you need it, just bring it back to room temperature (it takes a few minutes).
- Stand mixer with whip
- Mixing bowls
- Baking paper or silicone mat
- Angled spatula
- 30 g Butter
- 200 g Eggs Around 4 eggs, at room temperature
- 75 g Almond powder
- 75 g Hazelnut powder
- 120 g Icing sugar
- 40 g Flour Type 45 if available
- 130 g Egg whites Around 4 whites, at room temperature
- 1 pinch Table salt For the egg whites
- 20 g Granulated sugar For the egg whites
- Bring the eggs and the egg whites (SEPERATELY) to room temperature.
- Preheat the oven at 210°C.
- Melt the butter around 50°C.
- Sieve the flour.
- Place the almond and hazelnut powders with the icing sugar and HALF of the eggs in the bowl of the stand mixer. Whip them for 8 minutes.
- Add the rest of the eggs and whip for 12 minutes.
- Add 3 to 4 table spoons of this mixture to the warm melted butter and whisk energetically until it's combined. This step will allow the butter fat to be combined easily to the eggs mixture (rich in water).
- Whisk the egg whites with the pinch of salt and add the sugar in three times until it forms a soft peak on the whip (a meringue). It must be quite soft so that it can be folded without "breaking" the foam.
- Fold gently 1/3 of the meringue into the eggs mixture, using a spatula.
- Add the flour (using the sieve) and combine gently.
- Add the rest of the meringue and combine gently. It's better to alternate adding the meringue/flour (sometimes I do it 2/3 times if I prepare a larger quantitly) so that the meringue stays foamy and the flour is combined evenly.
- Add the butter mixture and combine gently (always using the spatula).
- The batter should be foamy.
- Spread the batter on the silicone mat or the parchment paper, use the angled spatula (it should be around 0.5cm thick). In general I use two trays in order to be able to cut 3 similar squares of 18cmx18cm.
- Bake for 7 to 8 minutes. Do not hesitate to turn the tray after 5 minutes. The color should be slightly golden (check picture below).
Yuzu and lemon syrup
The syrup can be prepared in advance, and placed in a sealed jar in the fridge for a maximum of 5 days, or in the freezer for a maximum of 2 months. When needed, just reheat it in a saucepan.
- 85 g White sugar
- 65 g Mineral water
- 60 g Lemon juice Freshly squeezed
- 60 g Yuzu juice
- Mix all the ingredients in a saucepan and bring to boil.
This crémeux (sort of custard) is tangy enough with a delicate yuzu flavor and balanced. You can prepare it in advance and store it in an airtight jar, with a cling wrap directly on the surface. You can freeze it for a couple of weeks (in a jar or in silicone molds) the taste won’t be affected. Whenever you need to use it, just whisk it energetically to smoothen it. It can be used to fill tarts, or to be inserted in an entremets to bring a creamy texture…
- Mixing bowl
- Hand blender
- Cling wrap
- 135 g Butter
- 2.5 g Gelatin Gold strengh (200 bloom)*
- 30 g Full fat milk Fresh if possible
- 80 g Yuzu puree Brand Ponthier if possible
- 30 g Lemon juice Freshly squeezed
- 1 piece Lemon
- 175 g Eggs Less than 4 eggs
- 105 g White sugar
- Cut the butter into small cubes and let it soften at room temperature for about 30 minutes.
- Soak the gelatin in cold water for 15 minutes.
- Heat the milk, yuzu puree, lemon juice and lemon zests. Do not boil.
- Whisk energetically the sugar with the eggs (just for a few seconds).
- Add 1/3 of the hot liquid to the eggs mix and whisk.
- Add this mixture to the hot liquid in the saucepan. Simmer over medium heat whitout stopping whisking. It should thicken after 2 to 3 minutes and start forming bubbles.
- Strain into a deep mixing bowl.
- Wring gently the gelatin and dissolve it in the hot crémeux.
- When the temperature of the crémeux is around 65°C, add the butter gradually (in 5 to 6 times) while mixing using the hand blender (to emulsify the preparation). Continue blending for 5 minutes to have a soft and light (not buttery) crémeux.
- Cover with the cling wrap directly on the surface and let it cool in the refrigerator for at least 30 minutes.
This mix can be prepared in advance and stored in the fridge for up to two weeks, or in the freezer for up to two months. So if you have any leftovers do not hesitate to store them.
- Stainless steel mixing bowl
- 80 g Hazelnut and almond praline Homemade if possible*
- 20 g Milk chocolate Jivara 40% of Valrhona
- 15 g Feuilletine flakes "Gavottes" biscuit available in supermarket**
- 1 pinch Fleur de sel French sea salt
- Melt the chocolate at 45°C using double boiler or microwave (not recommended).
- Add the praliné. If you want to have a less sweet crunch, you can replace 20g of praliné with hazelnut paste. You can prepare the paste by roasting raw hazelnuts for 15 minutes at 150°C, then peeling them mixing them (once cool) with high-speed blender until getting a smooth and creamy paste.
- Add the salt and the feuilletine flakes and combine.
This is what the Joconde cake looks like once baked:
Reheat the syrup.
Cut out 3 squares of Joconde cake, 18cmx18cm. Punch each of them with the yuzu syrup on both sides.
Place the first square on a tray lined with silicone mat or parchment paper. Spread the praliné then let it set for 5 minutes in the freezer.
Meanwhile, carefully spread 3/4 of the yuzu crémeux over the surface of the two other squares. Equalize using an angled spatula to get two smooth thin layers (they should be less than 5mm). If needed, let the crémeux set in the freezer for 10 minutes.
Spread the rest of the yuzu crémeux on the square with the praliné crunch (the yuzu layer should be less than 2mm thick).
Place the first square with the yuzu crémeux only. Lay on the square with the praliné. Place the last layer of cake with the crémeux and press gently.
Let the cake set in the freezer for at least 30 minutes.
Cut out 5 rectangular slices 3.5cm thick. Flip them such that the layers are visible on the top. Press them again each other to form a square of 18cmx18cm. You can add white chocolate strips to cover the sides and have a nice finishing.