Peel and dice 2 bananas and sprinkle with 1 tablespoon lemon juice. Cream fat, salt, sugar and vanilla sugar with the whisk of the hand mixer. Stir in the eggs one after the other. Stir in sour cream. Mix flour, cocoa and baking powder and stir in by the spoonful.
Fold banana cubes and 2 packs of Rolos® into the sponge mixture. Pour the dough into a greased and flour-dusted ring cake mould (2.5 litres capacity). Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 60 minutes. Cover after 50 minutes if necessary. Remove the cake from the oven and let it cool down on a cake rack for 10 minutes. Turn the cake out of the tin and let it cool down completely. In the meantime, roughly chop the chocolate coating and melt it on a hot water bath. Coat the cake with chocolate coating and let it dry for about 1 hour. Shortly before serving, cut 1 banana into 2 cm wide slices and sprinkle with 1 tablespoon of lemon juice.
Turn the cake out of the tin and let it cool down completely. In the meantime, roughly chop the chocolate coating and melt it on a hot water bath. Coat the cake with chocolate coating and let it dry for about 1 hour. Shortly before serving, cut 1 banana into 2 cm wide slices and sprinkle with 1 tablespoon of lemon juice. Place the banana pieces and 1 pack of Rolos® alternately on wooden skewers. Decorate cake with skewers