Preheat the oven to 180'C.
Place the chocoalte in a heatproof bowl over a pan of simmering water. Leave to melt thoroughly.
Beat together the butter and the sugar until smooth and creamy. Add the egg yolks one a time, beating each one before adding another. Add the melted chocolate, ground almonds and the orange flower water. Combine well.
In a separate bowl, whisk the egg whites until they form soft peaks. Add one third to the chocolate mixture to loosen it and then gently fold in the rest. Pour into a baking tin with a removable base and bake for 45 minutes. Check the torte is cooked by inserting a skewer into its centre: if it comes out clean, the torte is ready.
Zest the lemon. Peel the ginger and finely grate.
Sift the icing sugar into a bowl and beat together with the mascarpone, the lemon zest and the ginger.
Remove the warm cake from the tin and cut into wedges. Serve on plates with a dusting of icing sugar or cocoa powder and finish with spoonful of cream.
«If you are making the cake ahead of time, keep it in the tin at room temperature and then warm through in the oven at 140'C for about 15 minutes to serve.»