Walnut Cake

Heat the oven to 350ºF/180°C. Grind the walnuts together with the breadcrumbs in a food processor. Put the egg whites in a large bowl for whisking. Whisk the yolks and sugar in a bowl set over the saucepan of simmering water (without letting the bowl touch the water), until they have tripled in volume and become thick, pale and ribbony. Take the yolk mixture off the heat. Scatter over the nut mixture, along with the chocolate (if adding) then drizzle over the butter and coffee. Fold very gently, to blend. Whisk the egg whites to stiff peaks, stir a spoonful into the batter to loosen it, then gently fold in the remainder.

Pour into a greased and parchment-lined 8-inch/20-cm round cake tin. Bake until a toothpick inserted in the centre comes out clean, 35 to 40 minutes. Remove from the oven and cool on a wire rack before flipping the cake out onto a serving plate. Decorate with a sifting of icing sugar and a few walnut halves. Some white blossoms look nice too. Serve small portions with whipped cream and chocolate shavings or with coffee ice cream.