Preheat the oven to 175 ° C. Grease a muffin tin or line it with paper liners.
In a bowl, beat the eggs, sugar, sweetener, vanilla sugar and salt until frothy. Then stir in the oil and yogurt. Mix the flour with baking powder and baking soda and add to the egg mixture. Peel the banana, cut into slices, drizzle with lemon juice and chop with a fork. Mix with the batter. Pour the batter into the muffin tin.
Put in the hot oven and bake for about 20 to 25 minutes. Let the muffins rest for about 5 minutes, then take them out of the mold and let them cool on the wire rack.