Chop 200 g chocolate. Heat 400 g cream, remove from heat and melt chocolate in it. Stir in espresso powder. Pour chocolate cream into a clean, dry mixing bowl. Cover directly on the surface with foil and refrigerate for at least 4 hours. Finely grind 150 g walnuts. Line the bottom of a springform pan (26 cm Ø) with baking paper
Separate the eggs for the sponge cake base. Beat the egg white with 3 tbsp. water until stiff. Gradually add 150 g sugar, vanillin sugar and salt. Stir in the egg yolks. Mix flour and baking powder, sieve onto the egg cream. Fold in together with the walnuts. Put the mixture into the mould and smooth it down. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for 25-30 minutes. Take out and let cool on a cake rack
Drain the cherries and collect the juice. Mix the pudding powder with 100 ml water until smooth. Boil up the juice in a pot. Remove from heat and stir in the pudding powder. Bring to the boil again while stirring and simmer for about 1 minute. Cover directly on the surface with foil and let it cool down. Coarsely chop 50 g walnut kernels. Caramelise 25 g sugar in a pan. Turn the walnuts in it and place them one by one on a piece of aluminium foil lightly coated with oil. Let them cool down
Remove the base from the pan and remove the baking paper. Cut the base in half horizontally once. Place a cake ring around the lower cake base. Whip the chocolate cream briefly with the whisk of the hand mixer. Allow the cream hardener to trickle in. Fold the cream into the pudding. Spread approx. 1/4 of the cream on the lower cake base, smooth it down. Spread the cherries on top. Add the rest of the cream and smooth it down. Place the upper cake layer on top, press down a little and chill for at least 2 hours
Chop 75 g of chocolate and melt over a warm water bath. Leave to cool until the chocolate thickens and becomes liquid again. Put cocoa with 600 g cream and 3 tbsp. sugar into a mixing bowl. Whip until stiff with the whisk of the hand mixer. Spread some of the cream on the cake. Pour the rest of the cream into a piping bag with a large star-shaped spout and squirt large, flat tuffs onto the cake. Sprinkle caramelised walnuts on the cake. Spread the thick chocolate with a spoon on the edge of the cake. Keep cool until serving
Waiting time approx. 5 hours