Mix eggs, sugar, salt and oil with the whisk of the hand mixer until smooth. Peel the bananas, weigh 375 g, crush them to pulp with a fork and mix with the sugar mixture. Mix flour, baking powder and baking soda, add to the banana mixture and mix everything. Chop the chocolate into small pieces with a knife and fold into the banana dough. Press the paper cups into the hollows of a 15 muffin tray and fill the cups to the brim with the dough. Bake in the preheated oven (electric: 175 °C/ gas: level 2) on the middle shelf for 20-25 minutes.
Let the muffins cool down in the baking tray for about 5 minutes, then remove them and let them cool down on a cake rack. Finely chop the chocolate coating and melt separately on a hot water bath. Spread cooled muffins e.g. with semi-bitter couverture and use a wooden stick to draw milk couverture stripes and waves on top. Results in approx. 15 pieces