Preheat a pan over medium heat.
Place flour, baking powder, baking soda, salt and sugar into the Thermomix bowl. Combine 10 sec/speed 10.
Add whey or buttermilk to the Thermomix bowl and blend 10 sec/speed 10.
Add melted butter and combine 10 sec/speed 6.
Place a little butter onto the preheated pan and drop spoonfuls of batter into the pan. Add a few sliced bananas on each pikelet. Cook until bubbles appear, turn over and cook for about 30 seconds to just caramelise the bananas and seal the batter.