Chocolate mousse layer cake

Serves 8-12

You will need:

• 100g butter, plus extra for greasing the tin

• 8 eggs

• 300g caster sugar

• 200g plain flour, plus extra for dusting the tin

• 75g cocoa powder

• 3 teaspoons baking powder

• ½ teaspoon salt

• 1 teaspoon vanilla extract

For the mousse, you will need:

• 275g dark chocolate, in drops or broken into pieces

• 6 eggs, separated

• 175g butter, softened

• 2 tablespoons rum, brandy, whiskey or orange liqueur, or 1 teaspoon vanilla extract 1 You will also need two 23cm-diameter cake tins with sides that are a minimum of 6cm deep. Preheat the oven to 180°C, 350°F, Gas 4. Butter the sides of the cake tins and dust them with flour, then line the base of each tin with a disc of baking parchment. 2 To make the sponge, first melt the butter and set it aside for a few minutes to cool until it is tepid. Put the eggs and the caster sugar in a large bowl or an electric food mixer. Using an electric hand-held beater or the food mixer, whisk the eggs and sugar for 6-8 minutes, or until the mixture is light and thick. To test if it’s thick enough, lift the whisk out of the mixture and draw a figure of eight in the bowl with the batter that’s left on the whisk: the ‘8’ should remain visible on the surface of the batter for a couple of seconds.

3 Sift in the plain flour, the cocoa powder, the baking powder and the salt, and fold them in gently but thoroughly, then pour in the vanilla extract and the cooled melted butter, and fold them in.

4 Before it has a chance to lose any volume, quickly divide the batter between the prepared cake tins, then bake the cakes in the preheated oven for 30-35 minutes, or until the mixture springs back when it is lightly pressed with a finger, and a skewer inserted into the centre of each cake comes out clean. 5 Remove the cakes from the oven, and allow them to cool in the tins for five minutes. Use a small, sharp knife to loosen around the edges of each tin, and carefully remove each cake, before transferring them to a wire rack to cool completely. 6 While the cakes are cooking or cooling, make the chocolate mousse. Put the dark chocolate drops or pieces, whichever you’re using, in a heatproof bowl and set the bowl over a saucepan of water. Bring the water up to the boil, then turn off the heat, and allow the chocolate to melt nice and slowly. 7 Beat in the egg yolks one at a time, then beat in teaspoon-sized pieces of the softened butter. Now add the rum, brandy, whiskey or orange liqueur, or vanilla extract, whichever you’re using, and keep beating until the mixture is smooth. Set it aside to cool while you whisk the egg whites. 8 In a spotlessly clean bowl or using the food mixer (having cleaned and dried the bowl and whisk), whisk the egg whites until they form stiff peaks. Fold one-quarter of the egg whites into the cooled chocolate mixture, then carefully fold in the rest until they are just combined, but the mousse mixture is still light. Set the mousse aside and leave it to cool at room temperature — not in the fridge, as the mousse will harden and become difficult to spread. 9 To assemble the cake, use a bread knife to carefully slice each cake in half horizontally. Place the bottom half of one of the cakes, cut-side up, on a plate or cake stand. Spread a ½cm-thick layer of mousse on the cake, then sandwich the other half of the cake on top, placing it cut-side down. Spread over more of the mousse, just as thickly, then sandwich the bottom half of the second cake on top, cut-side up. Repeat, until you have four layers of cake sandwiched together with three layers of mousse. Cover the top and sides of the assembled cake with the remaining mousse, smoothing it with a palette knife. Place the cake on a large plate to serve. If you have chocolate curls (see Rachel Recommends, left) decorate the cake with these and dust it with icing sugar, or some crystallised primroses (see In Season, left).