For the base, whisk butter and 150 g sugar with the whisk of the hand mixer until white and creamy. Stir in eggs. Mix flour, hazelnuts, gingerbread spice and baking powder. Alternately stir in 100 ml milk. Put the dough into a greased springform pan (26 cm Ø) sprinkled with flour and smooth it down. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 50 minutes. Take out of the oven, carefully loosen the springform ring and put the cake in a cool place
In the meantime, boil 400 ml of milk up to about 6 tbsp. Stir pudding powder, 6 tbsp. sugar and remaining milk until smooth. Stir into the boiling milk, bring to the boil and simmer for 1 minute. Remove from the heat, place foil directly on the surface and allow to cool to room temperature. Peel the mango, cut the flesh off the stone and dice
Soak gelatine in cold water. Cut the cake in half horizontally. Place a cake ring around the bottom half. Squeeze the gelatine, dissolve in warm water. Stir 2 tbsp. pudding into the gelatine. Stir the mixed gelatine into the rest of the pudding. Cool until it begins to set. Whip 100 g cream until stiff. Fold the mango, lemon juice and cream into the pudding. Spread the cream on the cake base and smooth it down. Pour the top half onto the cream and chill for about 2 hours
Break the chocolate into pieces and put them in a pot together with 100 g cream and coconut oil. Melt at low heat while stirring. Remove the cake from the cake ring and spread icing on the cake. Refrigerate the cake again for about 1 hour
Waiting time approx. 5 hours