For the banana chocolate muffins, cut the ripe bananas into cubes, sprinkle with a little lemon juice. Coarsely chop the chocolate. Beat the eggs until frothy, then add the sugar, vanilla sugar and cinnamon.
Add a dash of rum if needed. Slowly add the oil. Mix flour with baking powder. Fold in banana and chocolate chips, then fold in flour, adding a little milk if needed.
Pour the batter into muffin tins and bake for about 20 minutes at 160 °.