Stir pudding powder, 1 tablespoon sugar and 6 tablespoons milk until smooth. Bring 340 ml milk to the boil, remove the pan from the heat and stir in the pudding powder. Place back on the stove, bring to the boil while stirring and simmer for about 1 minute.
Pour the pudding into a mixing bowl and cover the surface with cling film. Let it cool down.
Whip the cream in a mixing bowl until stiff. Add 200 g sugar, vanillin sugar, salt and eggs. Mix flour and baking powder and stir in briefly. Spread the dough on a greased, floured baking tray (approx. 36 x 41 cm) and bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see
manufacturer) Pre-bake for 12-15 minutes.
Melt 125 g butter in a saucepan, add 100 g sugar and 6 tbsp milk and mix well. Fold in the hazelnut flakes. Take the cake out of the oven. Spread the hazelnut icing evenly on one half of the cake (36 x 20.5 cm).
Cover the free dough half with aluminium foil and bake for another 14-15 minutes at the same temperature until golden brown. Remove and allow to cool.
Warm the nougat over a warm water bath. Whisk 125 g soft butter until white-creamy with the whisk of the hand mixer. Add lukewarm, soft nougat mass in 2-3 portions and fold in.
Whisk lukewarm pudding with the whisk of the hand mixer until smooth and stir into the nougat butter cream by the spoonful.
Cut the cake crosswise into 4 strips (each approx. 10 cm long). Remove the strips from the baking tray. Lift the strips without topping onto a long plate or board. Spread evenly with nougat butter cream.
Cut the nut strips into about 8 pieces each and place them on the nougat strips. Chill for about 2 hours, then cut into pieces and arrange on a cake plate.