Wow i am going in back in time with this old classic.  My inspiration for this dessert, was simple really.  Here in Otago, New Zealand we have an abundance of big fat, juicy cherries - hence Black Forest Gateaux.

150 gm dark chocolate (54% cocoa solids)
150 gm butter, softened
170 gm caster sugar
6 eggs, separated
150 gm self-raising flour, sifted
3 tsp cornflour
50 ml kirsch, plus extra to drizzle
250 ml (1 cup) pouring cream

To serve: chocolate curls (see note)

Cherry compote
330 gm (1½ cups) caster sugar
500 gm pitted cherries

Ganache
150 gm dark chocolate (54% cocoa solids), coarsely chopped
140 ml pouring cream

1. For cherry compote, combine sugar and 500ml of water in a saucepan and cook, stirring over medium heat, until sugar dissolves. Bring to the boil, add cherries, bring to boil again, reduce heat and simmer until cherries are tender (5 minutes). Remove from heat and set aside. Makes 1 litre of cherries and juice.

2. Preheat oven to 175C. Melt chocolate in a heatproof bowl over a saucepan of simmering water. Cool slightly. Beat butter and 150gm caster sugar in an electric mixer until pale and creamy (4-8 minutes), then add egg yolks one at a time, beating well after each addition. Add melted chocolate and stir to combine, then fold in flour in batches. Whisk egg whites to soft peaks, then fold through chocolate mixture. Pour into a greased and baking paper-lined 23cm spring-form pan and bake until a skewer withdraws clean (30-40 minutes). Remove from pan and cool on a wire rack.

3. Meanwhile, drain juice from cherries (reserving 180ml and discarding remaining). Place cherries in a bowl. Mix cornflour with 20ml reserved cherry juice to make a paste. Combine remaining cherry juice, drained cherries and cornflour paste in a saucepan. Stir over medium heat until mixture boils and thickens (2-3 minutes). Add 30ml kirsch and set aside to cool.

4. For ganache, melt chocolate and cream in a heatproof bowl over a saucepan of simmering water (3-5 minutes). Remove from heat and stir until smooth and glossy.

5. Whisk cream and remaining sugar until stiff peaks form, add remaining kirsch and whisk briefly to combine. Refrigerate until ready to assemble.

6. Halve cake horizontally, drizzle base generously with kirsch, spread with cream and spoon over cherry compote. Sandwich with top half of cake. Drizzle with more kirsch, then pour over ganache and scatter with chocolate curls.

Note: For chocolate curls, melt dark chocolate, spread thinly onto a marble slab or inverted heavy tray, set aside until firm. Scrape with a knife at a 45-degree angle (away from you) to create curls.