Step 1

For the sponge, heat oven to 180C/fan 160C/gas 4, then grease and line the base of a deep 22cm springform cake tin. Finely chop the toasted hazelnuts in a food processor, then tip into a bowl with the sugar, flour and bicarbonate of soda. Whisk the egg whites until stiff, then quickly stir the butter, milk and yolks into the dry ingredients. When the mixture is smooth, stir in one-third of the egg whites, then gently fold in the rest. Pour the mixture into the prepared tin, bake for 40-50 mins until the cake is golden andspringy to touch, then allow to cool.

Step 2

For the mousse, melt the chocolate in a glass bowl set over a pan of barely simmering water, then let it cool slightly. Soften the gelatine in water, squeeze out, then put in a small pan with 100ml of the cream. Gently warm over a low heat until the gelatine is melted (you shouldn’t be able to see any clear streaks in the cream), then tip into a bowl with the remaining cream and egg whites. Make sure you thoroughly scrape out the pan so no gelatine is left behind. Beat until it holds its shape, then spoon a quarter of this creamy mixture into the melted chocolate. Mix briefly until smooth. Fold in the remaining cream mix and raspberries, swirling the mixture so the berries begin to marble the mousse, then set aside until the cake is cool.

Step 3

To assemble, split the sponge in half and re-line the base of the cake tin with baking parchment. Use a long continuous strip of baking parchment to wrap around and line the inside, as this will help to make the sides of the finished torte look smooth. Press the bottom half of the cake back into the tin, sprinkle with half of the liqueur, then gently spoon over the mousse. Sprinkle the cut side of the top cake with the remaining liqueur and put this, liqueur-soaked side down, on top of the mousse. Press down gently, wrap the entire tin in cling film, then chill overnight.

Step 4

To serve, remove the torte from the fridge about 1 hr before you want to eat it, release from the tin, then gently peel off the baking parchment. Lightly dust the top of the torte with icing sugar, then pile on the chocolate curls (see box, below) and a few raspberries.