Prep time: 40 mins; cooking time: 15-20 mins, serves 10-12

I To make the sponge, heat the oven to 170G. 150 C fan, 325 F, gas 3. Place the egg yolks and sugar in a bowl and whisk with an electric mixer until pale and thick. Sift the cocoa powder over the top and fold in.

2 In a separate bowl, whisk the egg whites until very stiff. Fold into the yolks; add a tablespoon first to loosen the mixture, then gradually add the rest until well combined. Pour into the tin, and bake on the centre shelf of the oven for 15 to 20 minutes, until well risen and springy to the touch.

3 Remove sponge from oven, sprinkle with cocoa, place a sheet of baking parchment on top and invert onto a chopping board. Peel off the lining paper; roll up the roulade tightly using the long side, using the baking parchment to help you. Set aside.

4 For the mousse filling, place the chocolate in a heatproof bowl over a pan of hot water When melted, remove from the heat; stir in the buffer Leave to cool slightly. Stir in the egg yolks and amaretto and mix well, In a clean bowl, whisk the egg whites until stiff, then gradually whisk in the sugar until the mixture is thick and glossy. Fold the egg whites into the chocolate mixture. In a clean bowl, whip the cream until soft peaks form.

5 To make the almond brittle, oil a baking sheet and keep to hand. Put the sugar in a saucepan and gently heat without stirring until the sugar dissolves, Increase the heat and boil for 2 or 3 minutes or until it turns a light golden brown. Stir occasionally to make sure it does not crystatlise. Tilt the pan now and then to ensure it all melts. Spread out the almonds on the baking sheet. Pour over the caramel, allow to cool completely then break into shards.

6 To assemble, unroll the roulade and spread with a good layer of the mousse filling, reserving the rest for the top. Spread the whipped cream gently over the mousse, and then re-roll the roulade as tightly as possible, using the paper to help you. Spread the remaining mousse all over the roulade and fork all over to produce a log effect Use the shards of almond brittle to decorate the top of the roulade. Dust with icing sugar and serve.

Get ahead This roulade will sit in the fridge for up to 2 days - just don?t add the almond brittle until you?re

ready to serve it