Preheat the oven to 180C/350F/Gas 4.
Lightly grease and line the bases of two 23cm/9in cake tins.
Place the eggs, sugar and melted butter into a bowl and whisk for 4-5 minutes, until thickened and very pale – when the whisk is lifted out of the bowl, a trail should be left behind.
Sift in the flour and cocoa powder and fold in gently.
Spoon the mixture into the two cake tins, dividing evenly, then tap to settle.
Place the tins on a baking sheet in the oven for 12-15 minutes until risen and just firm to the touch – you do not want to overcook a genoise sponge, as it will become dry.
Remove from the oven and cool briefly before tipping out onto a rack to cool completely.
For the filling, whip the cream to soft peaks and fold in the kirsch and icing sugar.
For the topping, place the sugar with 125ml/4fl oz water into a pan and slowly bring to the boil until the syrup reaches 121C/250F on a sugar thermometer, then remove the pan from the heat.
Meanwhile, place the egg whites into a clean bowl with a squeeze of lemon juice, and whisk until firm peaks form.
With the beater at its lowest speed, pour in the sugar syrup, in a steady stream, making sure it is clear of the beaters.
Continue beating for about five minutes, until the meringue is tepid.
Add the butter and continue to beat until it is all incorporated. Then beat in the chocolate and make sure it is all incorporated.
To serve, cut the sponges in half horizontally so that you have four thin layers of sponge.
Place one piece of sponge onto the serving plate and spread over a third of the cherry jam, then a third of the kirsch cream.
Repeat with the other sponges and remaining jam and cream until you have a stack of four sponges with three layers of jam and cream.
Spread the chocolate topping over the gateau to cover completely.
Decorate with the fresh cherries and chocolate sprinkles.