RECIPE: I had some chocolate ganache left over from another recipe, so L’Opera seemed like a good option. Opera Cake is joconde sponge painted with coffee syrup and layered with coffee buttercream and chocolate ganache, and topped with a chocolate glaze. While you might expect this cake to be a sugar-overload, it had a light coffee flavour that worked well with the light sponge. It’s kind of a French version of Tiramisu. I halved the recipe, and still had a LOT of cake. If you’re halving a recipe, it’s not a bad idea to write the halved amount in pencil on your recipe, so you don’t forget halfway through…
COMPONENTS: I was pleasantly surprised that all the components of this cake were easy to prepare. Having your butter at ‘room temperature’ for buttercream means about 20 degrees (not the temperature of my kitchen, which is often 30 degrees!). In the process of halving the recipe, I added the full amount of sugar to the egg whites. I discovered that it’s not possible to bring additional egg whites to a soft peak and add them to a meringue – the air went out of the whole lot very quickly, so I had to start the eggs again, made the full recipe for the cake component and ended up with some spare joconde for the freezer.
ASSEMBLY: To get an even sponge layer, flip the sponge onto a flat surface lined with baking paper so that both sides are flattened. To get a much sharper finish than I achieved, place the top layer of sponge on the cake upside down so the flattest side is up. Use a palette knife to flatten a thick layer of buttercream, then cool before adding the glaze.
IMPRESSION: I loved this surprisingly easy cake for the light coffee flavour and light texture, didn’t find it difficult and would definitely try it again, and it even freezes well.
Recipe from Patisserie by Christophe Felder.