1. Preheat the oven to 180°C (350°F, gas mark 4). Grease and line a deep 15cm (6in) round cake tin.
2. Using an electric mixer, whisk together the egg yolks and sugar until pale and thick. Fold in the cocoa powder and flour (the mixture should be very thick). Using a clean whisk, whisk the egg whites in a separate bowl until stiff. Fold half the egg whites into the cocoa mixture, then gently fold in the rest. Spoon the mixture into the prepared tin and bake for 25-30 mins or until the cake is well risen and firm to the touch. Leave to cool for 5 mins in the tin, then turn out on to a wire rack.
3. For the kirsch syrup, heat 125ml (4fl oz) water with the sugar and kirsch in a small pan until the sugar dissolves. Then turn up the heat and boil for 3-4 mins or until the syrup thickens.
4. Carefully slice the cake into three even-size horizontal layers. Whip the double cream with the caster sugar and kirsch until thick. Spoon enough of the kirsch syrup over the cake layers to moisten, then spread two layers with the jam. Set one of the jam-covered layers on a plate, cover with the whipped cream and scatter with half the cherries. Top with the second jam-covered layer and repeat. Pop the final cake layer on top, spoon over the rest of the cream, then loosely cover and chill for 4 hours.
5. Decorate with the plain dark chocolate shavings, dust with the sifted cocoa powder and serve.

Nutritional information

Guideline Daily Amount for 2,000 calories per day are: 70g fat, 20g saturated fat, 90g sugar, 6g salt.