For the crumbles, put 75 g flour, cocoa, salt, 1 packet of vanillin sugar, 75 g sugar and 75 g fat in flakes in a mixing bowl and work into crumbles using the dough hooks of the hand mixer. Coarsely chop the chocolate coating and melt it on a warm water bath. Leave to cool slightly. Cream 100 g fat, salt, 1 packet vanilla sugar and 200 g sugar. Stir in the eggs one after the other. Mix 150 g flour and baking powder and stir in.
Pour in chocolate coating while stirring constantly. Line the hollows of a muffin tray (12 hollows) with 1 paper sleeve each. Spread the dough evenly in the troughs. Add crumbles. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 30 minutes. Remove from the oven, place on a rack and allow to cool. Whip the cream until stiff, adding 2 tablespoons of sugar. Peel the bananas. Cut 1 banana into slices and sprinkle with lemon juice. Cut the remaining bananas in half lengthwise and cut them into small pieces. Take off 1/4 of the cream. Fold the chopped bananas into the remaining cream.
Peel the bananas. Cut 1 banana into slices and sprinkle with lemon juice. Cut the remaining bananas in half lengthwise and cut them into small pieces. Take off 1/4 of the cream. Fold the chopped bananas into the remaining cream. Remove the paper sleeve from the muffins. Cut the muffins open and fill with banana cream. Decorate the lid with remaining cream, banana slices and chocolate sprinkles