I am venturing back into the land of Nigella Lawson this week. I make a lot of Nigellas recipes. Here Tarragon Chicken is one of my all time favorite weeknight suppers as well as her Watermelon, Red Onion and Feta salad which is great for picnics and buffets. He recipes are always simple, straightforward no nonsense affairs that take no time to put together and always please. This one is no exception. I happened to see a post on Nigellas Facebook page for this recipe and I remembered that I had seen it in her “Feast” book and knew that it was on my “want to try” list. I got out the book and saw that I even had the page marked with a “make this” sticker. This Facebook post was just Nigellas gentle nudge to me that now was the time to try it.
As most of Nigellas recipes, this one is easy to put together. I did the whole thing by hand. I guess I just didn’t feel like pulling out all the kitchen paraphernalia and it certainly wasn’t necessary for this recipe.
She even recommends that you can make the cake with a store bought cake but that isn’t really my style and this chocolate sponge is just too easy.
Sift together flour, cornstarch and cocoa and set aside. Whisk egg yolks and sugar together until slightly thickened. In a separate bowl, whip egg whites until frothy then continue to whip while slowly adding sugar until stiff glossy peaks form. Fold in the egg yolk mixture, then fold in the dry ingredients until combined. The batter has a fluffy, mousselike texture. Pour into a buttered and lined springform pan and bake for 30 minutes. When baked the cake will rise almost to the top of the pan. The cake needs to be cooled entirely in the pan as it is very delicate. When cool the cake will have shrunk to about an inch high. This cake is to be sliced into 3 layers. A word of warning here. The cake is extremely moist and very delicate. You will need a cake lifter or several cardboard cake rounds to deal with these extremely delicate layers. Nigella describes this cake as “silicon springy” and she isn’t kidding. While it is possible to slice the cake into 3 very thin layers, you may want to just sip it and just slice it in half.
For the filling, combine sugar, egg yolks and rum and whisk over simmering water until the mixture thickens (it will only thicken to a consistency of heavy cream). Remove from the heat and continue whisking to cool the mixture, then set aside to cool completely. While it is cooling, whip heavy cream until soft peaks form and set aside. When the yolk mixture is cooled, fold in mascarpone cheese until combined, then fold in the whipped cream and a chill until needed.
The cake is assembled in the springform pan as it is rather delicate and I would recommend using a cake round to assemble it on. Place the first layer in the pan, brush with the syrup being careful not to make it too wet. Spread a thick layer of the filling on the cake. (I took artistic license here and added pistachios on top of the filling. Nigella only uses pistachios as a decoration here but I like them and wanted more). Continue in the same manner until all the layers have been added and filled. Cover the cake with plastic wrap and chill overnight to firm it.
Nigellas recipe has a chocolate frosting and she only frosts the top of the cake. I am not much of a fan of cakes with unfrosted sides. They just always seem unfinished and messy to me. I decided I wanted to cover the entire cake so I just skipped her frosting and made a chocolate pouring glaze to cover the entire cake.