Tiramisu Opera Cake

Yields: 8 servings

We developed this recipe by adapting several different opera cake and frosting recipes. We drew inspiration from BBC, The Food Network, Epicurious, The Tough Cookie, and The Cupcake Project.

Ingredients

For the almond joconde

½ cup ground almonds

¼ cup all-purpose flour

¼ teaspoon salt

3 eggs

3 egg whites

½ cup granulated sugar, divided

For the tiramisu buttercream

3 egg yolks

6 tbsp granulated sugar

2 tbsp espresso

1 tbsp Marsala

½ cup butter, cubed and softened at room temperature

4 oz. mascarpone cheese, at room temperature

For the coffee syrup

½ cup espresso, cooled

2 tbsp Marsala

For the chocolate ganache

6 oz. bittersweet chocolate, roughly chopped

¾ cup plus 1 tablespoon heavy cream, divided

1 tsp vegetable oil

For Decoration

1 oz. chocolate, melted

Directions

1. Make the joconde sponge. Preheat the oven to 400 F. Line an 11x17 jelly roll pan with parchment paper or nonstick foil.
2. Sift together the ground almonds, flour, and salt.
3. With an electric mixer, whisk together the three egg whites with ¼ cup of the granulated sugar in a mixing bowl. Whisk on low speed for two minutes, medium for two minutes, and high until they form stiff white peaks.
4. In a separate mixing bowl, whisk together the three whole eggs and remaining ¼ cup of sugar until thick and pale. Fold in the dry ingredients.
5. Mix about ¼ of the whipped egg whites into the flour/egg mixture to lighten the mixture. Gently fold in remaining egg whites, taking care not to knock out the air from the egg whites.
6. Spread the batter evenly over the pan, and bake for 7-10 minutes, until the top of the sponge is golden. Let cool completely.
7. Make the buttercream. In a mixing bowl over a pot of simmering water, mix together the egg yolks, sugar, espresso, and Marsala. Take care that the bottom of the bowl doesn’t touch the simmering water. Stir the mixture constantly, to prevent it from scrambling. Heat until the sugar has dissolved; the mixture should be fairly hot, and it should not feel grainy when you rub a little bit between your fingers.
8. Whip the egg yolk mixture until it is it is thick and pale, and the bowl cools to room temperature. While whisking constantly, gradually add the butter a few cubes at a time, followed by the mascarpone cheese a spoonful at a time. It is important that the butter and mascarpone are at room temperature, so that they incorporate smoothly into the egg yolk mixture.
9. For the coffee syrup, mix together the espresso and Marsala.
10. Make the chocolate ganache. Heat ¾ cup of the cream in the microwave or in a pan until it begins to simmer. Add the chopped chocolate. Let sit for 30 seconds, then stir until it forms a smooth ganache.
11. Assemble the cake. Peel the sponge away from the parchment paper, and cut into 3 even rectangles, about 11 x 6 inches. (11 x 5 ⅔, if you want to get technical).
12. Generously brush one of the cake pieces with the coffee syrup. Spread about half of the buttercream frosting over the cake.
13. Top with another cake piece, and brush again with the coffee syrup. Spread with about ⅓ of the chocolate ganache.
14. Top with the remaining piece of cake, and brush with the coffee syrup. Spread the remaining buttercream in an even layer.
15. Refrigerate for at least 2 hours, or overnight.
16. Add the remaining one tablespoon of heavy cream to the remaining chocolate ganache, and reheat until it is melted and smooth again. Mix in the vegetable oil. Pour over the top of the opera cake, using an offset spatula to spread it in an even, smooth layer, if necessary. Refrigerate for another 15 to 30 minutes.
17. Decorate the cake. Melt the chocolate and pour into a ziploc bag with the tip snipped off, or a piping bag.