Chop the almonds. Wash pumpkin and apples. Clean pumpkin and cut into slices. Remove seeds, grate pumpkin and 1 apple roughly. Whip butter and 200 g sugar with the whisk of the hand mixer until creamy.
Stir in the eggs one by one. Mix flour, salt and baking powder. Stir sour cream and flour mixture into the egg mixture one after the other. Stir in almonds, pumpkin and apple.
Fill the dough into a greased and flour-sprinkled square springform pan (24 x 24 cm) and smooth it down. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for about 1 hour.
Remove the cake from the oven, let it rest in the mould for about 10 minutes, remove from the mould and let it cool down on a cake rack.
In the meantime, quarter the remaining apples, remove the core and cut into thin slices. Bring 4 tbsp. sugar and 60 ml water to the boil in a pan. Add apple slices, bring to the boil again and steam in the sugar syrup for about 3 minutes.
Let it cool down. Mix cream cheese, icing sugar and cream. Spread the cream on the cake. Cut cake into pieces and spread apples on top.