Boil 200 ml of milk. Stir pudding powder, 2 tablespoons sugar and 50 ml milk until smooth. Stir into the boiling milk, bring to the boil and simmer for about 1 minute. Remove from the heat, pour into a bowl and cover with foil.
Leave the pudding to cool for at least 2 hours.
Chop 250 g chocolate. Melt butter and chopped chocolate in a pot. Beat the eggs and 150 g sugar with the whisk of the hand mixer until creamy. Stir the butter and chocolate mixture into the egg mixture.
Mix flour and almonds and stir in.
Pour the dough into a greased, floured box form (11 x 30 cm; 1.75 litre capacity) and bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for about 50 minutes.
Take out and let cool on a cake rack for about 30 minutes. Turn out of the tin and let it cool down.
Soak gelatine in cold water. Stir the pudding until smooth, add sour cream and 25 g sugar. Wash the currants, drain well and remove the berries from the panicles. Dissolve gelatine, stir in 5 tbsp. pudding cream, stir the mixture into the remaining pudding cream.
Stir in 150 g currants. Chill the cream until it starts to gel.
Cut the cake in half horizontally. Spread the cream on the lower cake base. Place the upper cake layer on top and chill for at least 1 hour.
Chop 200 g chocolate. Heat cream in a pot, add chocolate and dissolve while stirring. Mix to a smooth glaze and let it cool down a little. Place the cake on a grid and cover with icing.
Sprinkle with the remaining currants and chill for another 30 minutes. Dust with icing sugar before serving.