Chocolate Truffle Opera Cake
Coffee French Buttercream
1/2 cup or 100g sugar
1/2 cup or 100g brown sugar
1/ 2 cup or 50g water
4 egg yolks (or 75g)
250g butter, softened (a cup plus a tablespoon)
1/2 tsp vanilla essence
2 1/2 ounces or 75g dark chocolate
1 tablespoon of instant coffee
Melt the chocolate in a bain marie or a double boiler. I use one of my metal bowls that fits neatly over one of my sauce pans. Let cool and set aside.
Dissolve the instant coffee in 3 tbsp boiling water. Let cool and set aside.
Cut the butter into small blocks.
Beat the egg yolks till in doubles in volume. This may take a while- like 7 to 10 minutes. I left it running in my mixer for quite a while.
Cook the sugars together with the water till the mixture reaches about 240F or 115°C. Slowly pour this mixture into the beaten egg yolks while beating continuously.
Continue mixing until the mixture cools down to room temperature. Place hand at bottom of mixer bowl to feel whether it is cool or not.
Add the butter a few blocks at a time, making sure that the butter is completely mixed into the mixture each time, until all the butter is used up.
Add the melted chocolate, mix evenly.
Mix the vanilla into the cooled coffee and pour that into the mix.
5 whole eggs + 1 egg yolk
120g icing sugar
160g Hazelnut meal or almond meal
40g cocoa powder
60g cake flour
1/2 tsp baking powder
1/4 tsp salt
40ml vegetable oil
In a separate bowl
3 egg whites
30g icing's sugar
1 tsp cornflour
a large mixing bowl, add the eggs, egg yolk and sugar. Beat the mixture till it
triples in volume and leaves a trail. This takes about 7 to 8 minutes. Be sure to
reduce the beater's speed to low and let it run for an additional minute to
reduce the large bubbles present in the batter.
Sift in the dry ingredients to the egg mixture in 3 separate portions and gently
fold in till you see no visible lumps.
Add the vegetable oil and again fold in gently till all is well combined.
Preheat the oven to 350F. Grease and line a 15 1/2 x 10 1/2 with parchment.
In a separate mixer bowl, add in the egg whites and beat till foamy. Gradually
add in the sugar and beat till soft peaks. Now add in the cornflour and continue
to beat till it is well combined and still peaks.
Fold the whites into the main batter in 2 separate portions until incorporated.
Pour the batter into a greased and parchment lined cake pan and bake in the
preheated oven for 20 to 30 minutes till the tester comes out clean. Tap the pan on the counter to get out air bubbles.
Cool completely on rack before slicing. When cooled, cut the cake in 4 equal portions.
600g dark chocolate, chopped into small pieces
300ml whipped cream
20g unsalted butter
1 pack of instant coffee mixed in 6 tbsp of boiling water
In a saucepan, heat the cream till almost bubbly. Pour the liquid over the chopped chocolate and butter. Leave the mixture without stirring for 5 minutes. After 5mins, stir the mixture till all the chocolate chunks are melted and its smooth and thick. Add in the coffee mixture, mix well. Let cool at room temperature (no chilling) for use later.
When assembling the cake- I find it much easier if the cake is frozen. The icing goes on nice. I freeze it again after the layers are assembled. I add the ganache on the cold cake and freeze it. Followed by another layer of ganache. The first one is to get the cake covered. The second layer is to make sure everything is covered and looking pretty. Thats not to say that I did an entirely great job though. As you can see in the photo below I have some cake showing. Eh- nobody complained.