Daring Bakers and the Opéra Cake

We're back, and this time in a pastry challenge worthy of a spot at the Olympics! This challenge was brought to us by Fran from Apples Peaches Pumpkin Pie, Ivonne from Cream Puffs in Venice, Lis from La Mia Cucina, and Shea from Whiskful.
An Opéra Cake is made up of five components: the jaconde, an almond sponge cake, a simple syrup to moisten the jaconde, a buttercream to fill some of the layers, a mousse to make up one of the layers, and a ganache to glaze the top. We were instructed to keep the flavors "light" -- no chocolate, cocoa, or coffee, and the color had to be light as well. Going ahead with that train of thought, I decided to turn my Opéra Cake into a "White Forest Cake"; white chocolate making up the ganache as per the given recipe, and cherry puree making up the simple syrup, buttercream, and mousse. It was my dad's birthday, and I typically make him a Black Forest Cake, though a walk on the light side is always a good idea.

After making all the components, I proceeded the next day with the assembly of the cake. In this picture, I have brushed the first layer with cherry simple syrup, flavored with the most hideous kirsch I've ever smelled.

(Actually, I've never used kirsch before, but after research found that Hiram Walker Kirsch was made from the pit of the cherry instead of the cherry itself. Obviously, bitterness came to mind, and it really didn't lend a cherry taste to the syrup. My mom tasted some of it and told me that it not only didn't remind her of cherry cough syrup, it tasted like cherry Listerine, complete with the intense throat-burning feel. On the label, there are directions for a strange cocktail flavored with the HW Kirsch, HW Amaretto, HW something else liquors, lemonade, and ice. I think this brand was just made to get drunk? I didn't research kirsch ahead of time, but I know what I will buy next when the ENTIRE bottle gets used... It'll most likely take over 1 1/2 years for that to happen. Maybe this is all my n00bness coming through. If you can, enlighten me on this subject!)

Here is the mousse layer. Very light and airy, though the cherry taste was missing. I pureed my own mix of frozen dark cherries with a bit of sugar, but I think I either needed to use sour cherries or add more sugar.

This is the completely assembled cake, finished with a layer of French buttercream. The buttercream curdled a bit after I added some of the cherry puree, but it remained smooth in feel. Maybe I reduced the butter by too much, as I used 2 1/2 sticks instead of 3 1/2, and perhaps I should have used at least 2 3/4, but I don't know. Also, the Swiss buttercream I made from the Perfect Party Cake challenge was not as achingly sweet as this was, but when fully assembled it wasn't overpowering.

A view from the side


Leftover scraps from trimming the sides

After setting in the fridge, a white chocolate ganache was poured on top. For extra flair, I decided to add drops of the remaining cherry syrup (I probably could have brushed more of it on the layers) and create a marbleized design.

When we were ready to have Dad's birthday Opéra Cake, I sliced and served everyone a piece. The overall reviews were in the positive, though we all agreed that it didn't really have much of a cherry taste. The jaconde was a favorite because it was light, nutty, and paired well against the smoothness from the buttercream and mousse. The mousse was favored for it's slight difference from the buttercream in that it wasn't as sweet and was more billowy, but the texture was smooth and very much "in rhythm" with the other components. As for the buttercream, it wasn't too sweet against the jaconde and mousse, but was slightly sturdier and basically, in both a different-yet-similar way of the mousse, was within the texture and feel of the jaconde and mousse. The white chocolate ganache, however, was really off. It's waxy, plasticy texture was a complete difference, and I couldn't even cut through it without all the fillings of the cake oozing out. I would have preferred a shell of just melted white chocolate to the waxiness of the ganache.

We all enjoyed another slice as a Memorial Day treat served with vanilla bean ice cream drizzled with cherry puree-syrup.

Thanks to the hosts for giving me a push! This recipe is one I might have noted, but put off until I forgot about it. Once again, I have expanded my baking repertoire! Don't forget to peruse the Daring Bakers' Blogroll to read other tales of the Opéra Cake.

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PEACH, ALMOND & VANILLA OPERA CAKE
This recipe was posted by Pam from Sugar Chef. The recipe is from the original posted by the hosts, but changed to make it fruit-flavored and with a fruit mousse instead of a white chocolate mousse. A big thank you from me to Pam, as I was looking for a way to incorporate fruit, but I didn't exactly know how to proceed.

6 Large Egg Whites (room temperature)
2 Tablespoons (30 grams) Granulated Sugar
2 Cups (225 grams) Almond Meal
2 Cups (225 grams) Powdered Sugar
6 Large Eggs (room temperature)
½ cup (70grams) Unbleached All Purpose Flour
½ Tablespoon Vanilla
3 Tablespoons (45 grams) Unsalted Butter (melted & cooled)

Line two ½ sheetpans with parchment paper. Butter the paper.
Sift together the almond meal and powdered sugar, set aside.
In a bowl of a 5 quart mixer using the paddle attachment beat the eggs to break them up. Add the sifted almond meal and powdered sugar mixture as well as the vanilla. Beat for 3 minutes.
Add the flour and mix on low speed just to incorporate.
In a clean bowl of a 5 quart mixer using the whisk attachment beat the egg whites to soft peak and while still beating slowly add the granulated sugar. Continue to whisk at high speed until the mixture is at full peak and glossy but not dry.
Fold this mixture into the egg, almond meal & powdered sugar mixture.
Remove ¼ cup of the mixture and stir into the melted butter. This will allow the melted butter to completely mix into the larger mixture. Fold everything together.
Weigh the mixture. Mine weighed 2 pounds 4 ½ ounces. Spread 1 pound 2 ¼ ounces into each prepared ½ sheetpan and bake in a 400 degree convection oven (425 degrees standard oven) for 7 minutes or until light brown.
Invert onto a clean sheet of parchment paper and peel off the parchment from the cakes. Turn over and use the parchment to cover the cakes. Let cool to room temperature then cover with plastic wrap to keep it air tight.

PEACH SYRUP
1 Cup Peach Juice (from IQF frozen peaches drained overnight)
2 Tablespoons Peach Schnapps
Sugar to taste if your peach juice is not sweet enough.

Bring the peach juice and sugar (if using) to a boil and reduce a little to a syrup consistency. Add the Peach Schnapps and refrigerate until ready to use.

PEACH BUTTERCREAM
2 Cups Sugar
½ Cup Water
2 Large Eggs
2 Large Egg Yolks
14 Ounces Unsalted Butter (room temperature)
1/3 Cup Peach Puree
In a 5 quart mixer beat the butter with a paddle attachment till light and free of lumps. Set aside.
Put the eggs and egg yolks in a bowl of a 5 quart mixer with the whisk attached. Whisk for a minute to break up the eggs.
Put the sugar and water in a sauce pan and cook without stirring until the mixture reaches 225 degrees. (Once the mixture reaches 210, start whipping the eggs at high speed.)
Lower the speed to medium high and pour the sugar mixture slowly down the side of the bowl. When it is all incorporated bring the speed back up to high and beat until cool (about 5 minutes).
Add the butter a little at a time whisking at high speed.
Whisk in the Peach Puree.

PEACH MOUSSE
4 Ounces Peach Puree
1 Ounce Granulated Sugar
1 ½ Gelatin Sheets (bloomed) (I used one packet of unflavored gelatin, though I think only half was needed to sub for 1 ½ sheets. I erred on the side of caution, just in case.)
6 Ounces Heavy Cream

Heat puree and sugar to about 86 degrees just to melt the sugar.
Add the gelatin and stir to dissolve.
Let the mixture cool to room temperature
Whip the cream and fold it into the puree mixture.

WHITE CHOCOLATE GLAZE
14 Ounces White Chocolate (I used Callebaut)
½ Cup Heavy Cream (I used 40%)

In the microwave bring the cream to a boil and pour over the chocolate. Stir with a whisk until the chocolate is completely melted. Use at 90 degrees.

ASSEMBLE THE CAKE

Line a baking sheet with parchment or wax paper.
Cut the cake so you have one piece 10” x 10” and one piece 10” x 5”. Repeat with the other cake. You will have two 10” X 10” and two 10” x 5”.
Put one of the 10” pieces on the parchment lined baking sheet. Moisten it with the peach syrup using a brush.
Spread a ¼” thick layer of peach buttercream over the cake. Put small diced pieces of fresh peach over the buttercream and push them down into the buttercream.
Put the two pieces of cake that measure 10” x 5” over this, fitting them together so you have a 10” x 10” square. Moisten with the peach syrup.
Put all of the peach mousse onto this cake layer and spread out evenly.
Put small diced pieces of fresh peach over the mousse and push them down into the mousse.
Put the last 10” square cake on top of the mousse layer. Moisten with the peach syrup.
Spread a ¼” thick layer of peach buttercream over the cake. Refrigerate at least 30 minutes.
Spread the white chocolate glaze over the chilled cake and return to the refrigerator.
Chill until set.