Method

1. Preheat the oven to 190C/375F/Gas 5. Grease and line two 23cm/9in sandwich tins

2. For the brownie base, melt 180g/6¼oz of the chocolate in a bowl set over a pan over simmering water. Chop the remaining chocolate and set aside.

3. Meanwhile, cream the butter and icing sugar together in a separate bowl until light, creamy and fluffy. Slowly whisk in the eggs, one at a time, until well combined.

4. Gradually beat in the flour until the mixture is very smooth. Slowly pour in the melted chocolate and fold it into the mixture, then fold in the chopped chocolate.

5. Pour the brownie mixture into the prepared sandwich tins and bake for 10-12 minutes. Reduce the oven temperature to 170C/325F/Gas 3.

6. Meanwhile for the meringue topping, whisk the egg whites and cream of tartar in a bowl until soft peaks form when the whisk is removed. Slowly whisk the sugar until smooth and glossy, then fold in the chopped hazelnuts with a metal spoon.

7. Spoon the meringue topping onto the cooked brownie base. Use a palette knife to smooth the meringue mixture in one sandwich tin and use a skewer to make peaks in the meringue mixture in the other tin.

8. Return the sandwich tins to the oven for a further 30 minutes, or until the meringue is golden-brown. Remove from the oven and set aside to cool. Carefully remove the cakes from the tin and set aside to cool completely on a wire rack.

9. For the filling, whip the cream and icing sugar together in a bowl until stiff peaks form when the whisk is removed. Fold in the raspberries.

10. To assemble, place the flat meringue brownie, meringue-side down onto a cake stand or large plate, spoon over the raspberry cream and top with the remaining cake, brownie-side down. Sprinkle over the chopped hazelnuts and pistachios.