Peel the bananas and crush them finely with a fork. Beat the banana puree, butter, sugar, lemon peel and vanilla sugar with the whisk of the hand mixer until foamy. Stir in the eggs bit by bit.
Mix flour and baking powder and stir in four portions. Add milk, almonds and nuts and mix. Fill the dough into a greased springform pan (26 cm Ø) with breadcrumbs and a tube bottom insert and bake in the preheated oven (electric range: 175 °C/ gas: level 2) for about 1 hour.
Remove the cake from the oven, let it cool on a cake rack, then remove it from the mould. Place the cake glaze in hot water for 10 minutes, cut open the bag and pour over the cake. Let the icing dry.
Before serving to decorate, whip cream until stiff, fill into a piping bag with star-shaped spout and squirt tuffs onto the cake. Peel and slice the banana, sprinkle with lemon juice and place in the cream tuffs.