Daring Bakers: Opera Cake

My second challenge for the Daring Bakers is gateau l'opera or opera cake. A multi-layered cake involving jaconde, a nut-based biscuit, buttercream, mousse, and a ganache glaze. I've never made this before, but I've certainly had it at some point in my life.

The recipe is quite long, so I won't reprint it here. It was based on the opera cake recipes in Dorie Greenspan's Paris Sweets and Tish Boyle/Timothy Moriarty's Chocolate Passion. May's challenge involved "light" colors and flavors. While opera cake is traditionally chocolate, the challenge required the DBs to look to non-chocolate flavorings. I decided to stick to the path of least resistance. The challenge recipe already used almonds, vanilla, and white chocolate, so I stuck to those flavors and added fresh strawberries. When I baked this, strawberries were running for $0.77 to $1.35 a quart. That's local Carlsbad strawberries, so the season was clearly in full-swing.

My favorite part of this challenge was the jaconde. I had tons of almonds on hand, which was a convenient coincidence. The cake is nutty and rich, although it came out too thin for me. I used two half-sheet cookie sheets, which is slightly larger than the jelly roll pans required in the recipe.

Next time, I will put all of the batter into one sheet pan, cut it into three pieces, and end up with a smaller cake. The almond meal is combined with whole eggs and sugar, then folded into whipped egg whites.

The beginning of folding... turned out a lot better than it looks!

The buttercream required a boiled sugar syrup that is cooked to 225 degrees F. I let mine go to 240 degrees F while I took this picture:

Turned out fine. The hot syrup is poured into eggs and egg yolks while they're being whipped in a mixer. There was a whole vanilla bean's worth of seeds in the syrup and I amped up the vanilla flavor by adding extract on top of the bean. Butter is added to the egg/syrup mixture to complete the buttercream. The end result is something like a pastry cream, with the extra vanilla being a nice touch.

I didn't find this recipe difficult, just time-consuming. The great thing about it was that all of the individual components could be made one at a time, then assembled later. So, I spaced it over a week in preparation for a belated Mother's Day in LA (Mom wanted to celebrate a week after Mom's Day proper, to avoid crowds).

Assembly was fairly easy. The jaconde was brushed with a simple syrup, which was flavored with limoncello, then covered with buttercream and strawberry slices (see first photo). This step was repeated once more, then topped with the last layer of jaconde. After that came the white chocolate mousse, which consisted of white chocolate melted with some heavy cream, then folded into whipped cream. After that, a white chocolate glaze was poured on top.

White chocolate overkill.

I would have thinned out the ganache glaze a little more, because it hardened quite a bit, making it like a white chocolate bar on top of a cake. Too much and too sweet. I would have also changed the mousse to a light lemon to bring out more of the strawberries.

The edges were trimmed off with a sharp knife to produce the final product. The too-thin jaconde led to sagging corners where the cake was thinnest. Hence, the slope of the cake.

Closer look at the layers.

Another DB challenge done! I can't wait for June's challenge. A big thank you to Ivonne, Lisa, Fran, and Shea for hosting!

And of course, HAPPY MOTHER'S DAY, Mom! I love you!