Opera Cake

Posted on October 10, 2012


Finished Opera Cake

This is probably my favorite cake – which is also a multi-step process.  Usually this is made as two large (half sheet) pans, but that is a lot of cake – so this is a smaller version.

Prep 1 half sheet pan (15×12 inches the biggest you have in your home kitchen) by coating it with non-stick spray, then cover with parchment, then spray the parchment.

Pre-heat the oven to 425° F

1.0 Cake – Traditionally Almond Cake, but in this case Hazelnut 

  • 3      ________________ egg whites (save the yolks for the buttercream)
  • 1 TBSP   ________________ sugar
  • 130 grams  ________________ hazelnut flour (ground hazelnuts, or almonds if you want)
  • 130 grams  ________________ confection sugar, sifted
  • 3   ________________ eggs
  • 32 grams  ________________ all-purpose flour
  • 3 TBSP   ________________  melted butter
  • 1 tsp   ________________ vanilla
  • 14 tsp  ________________ salt
  • In a large bowl, or stand mixer whip the egg whites, with the sugar.
    • Start the whites with a whisk, by hand, to avoid un-whipped egg whites from collecting in the bottom of the bowl
  • Whip to stiff peaks – stiff but not dry.
  • Scoop whipped egg whites into another clean bowl (I do this, just to reuse the same bowl)
  • Beat the yolks, confection sugar.
  • Add the ground hazelnuts
  • Mix in the cooled melted butter.
  • On low, add in the flour, until just combined
  • Remove from mixer, and fold in one third of the egg whites.
  • Fold in the rest of the egg whites, carefully.
  • Distribute into the pan
  • Bake for 5 to 7 minutes.  Check at 5 minutes.
  • Remove, and let cool.
  • Flip onto a cooling rack, and pull the parchment off, cover the cake with plastic wrap to keep it from drying out.
  • You can also wrap the cake and freeze it.
  • (Note: You can also make these cakes in 3 pans, dividing the batter evenly, which is what you see in the pictures)

2.0 Espresso Syrup

  • 12 Cup  ________________ simple syrup (using 2 C sugar to 1 C water)
  • 2 oz   ________________ espresso (fresh shot, or 2 TBSP powder, in 2 TBSP water, but ick)
  • 12 oz  ________________ dark rum (cognac, bourbon, though alcohol is not strictly necessary here)
  • Pull espresso shot, or brew a moka pot of espresso.  Or mix the instant powder with the water.
  • In a small spray bottle, mix the espresso, and simple syrup, and rum.
  • Close, and shake.
  • Alternatively, whisk together all ingredients in a bowl, and find your pastry brush.

3.0 Espresso French Buttercream

  • 1  ________________ egg
  • 3 ________________ egg yolks (the ones from before!)
  • 1 oz ______________ Espresso (fresh shot, just like the espresso syrup)
  • 250 grams  _________ granulated sugar
  • 2 TBSP ____________ water
  • 1 tsp ______________ vanilla extract
  • 1 tsp ______________ corn syrup (to keep the sugar from crystallizing)
  • 200 grams __________butter (14 TBSPS, most of 2 sticks, room temp)
  • 100 grams __________confectioners sugar
  • Place egg and egg yolks in stand mixer, and beat with a TBSP of the sugar.
  • Place the rest of the sugar, and the water in a sauce pan.
  • Bring to a boil.
  • Cook to 250° F – then turn off the heat, add the vanilla extract, corn syrup, and the espresso.  Stir to combine.
  • Let cool a little, then stream it into the mixer, while it’s mixing.
  • Cut the butter into small pieces, and add a little at a time, until all the butter is mixed in.
  • Add the confectioner’s sugar – keep whipping until it has a nice texture.
  • Set the bowl aside.

4.0 Ganache, Dark Chocolate & More Espresso

  • 10 oz    ________________ Bittersweet Chocolate, finely chopped, or melted – I use our warming to melt it)
  • 12 Cup ________________ Cream
  • 12 Cup ________________ Whole Milk
  • 4 TBSPs  ________________ Butter
  • 1 tsp   ________________ glucose syrup (or corn syrup, about a squirt)
  • 2 TBSPs   ________________ Crushed Espresso Beans (or, 2 TBSP of the espresso syrup)
  • Heat the cream, don’t let it boil.
  • Add the espresso beans to the cream and let it sit for 20 minutes, while you deal with the chocolate.
  • Melt the chocolate, in a double boiler, or lightly in a microwave, or however you want.
  • Pour the cream over the chocolate (straining out the espresso beans)
  • Whisk to combine, starting in the middle.  Don’t use a spatula or spoon on ganache. Whisk.
  • Add in the butter, and glucose syrup, whisking to combine.
  • Set aside, and wait for it to cool to at least 70° F or room temperature, before beating lightly.
  • Don’t beat as much as you would for ganache icing, but don’t leave it as dense as truffle filling.
  • Tip: Melt all the chocolate at once, and keep the glaze chocolate warm over some simmering water, a heating pad, or if you’re hardcore like me, a tempering machine.

5.1 Assembly

  • Fine a piece of cardboard, or a cake board, and cut it into a 12×5″ rectangle
  • Use this as a guide to cut the cake into thirds that are 5″ by 12″ – or 3 even pieces, if you used a different size pan.
  • Get out a new sheet pan.
  • Put a tiny bit of buttercream on the cake board, and place your bottom layer on it. (Use the ugliest layer for the middle)
  • Coat the top of the cake layer in Espresso Syrup – easier with the spray bottle.
  • Spread 14 of the buttercream (or a reasonable amount), on the layer.
  • Place the middle layer on top.
  • Espresso Syrup the top of that layer
  • Spread most of the ganache on top
  • Place the last layer on top of the ganache
  • Espresso Syrup the top of the layer, spread a light layer of buttercream on top, and some ganache if you have some left.
  • Chill the cake, for at least an hour, before you glaze it.
  • If for some reason you freeze it, let it come to fridge temp  – don’t glaze it while frozen.
  • Save the rest of the buttercream and ganache… for snacks
Opera Cake Layers

Opera Cake Layers

5.1 Glaze

  • 5 oz    ________________ Bittersweet Chocolate, finely chopped, or melted – I use our warming to melt it)
  • 8 TBSPs  ________________ Butter, melted, clarified (scoop off the bubbly browning bits)
  • Melt the chocolate (double boiler, etc)
  • Whisk in the butter.
  • Place the cake on a rack on a sheet pan, and tilt the pan up.
  • While the glaze is still warm.
  • Pour the glaze over the top and let it stream over the cake.
  • Decorate with strips of white chocolate, or white fondant icing – making lines, and pulling lines through it.  Or just leave it plain.
  • Allow to set before serving.

Half finished Opera Cake – hanging out in my fridge.

Posted in: Cake, Complicated, Recipe