1. Preheat the oven to 350˚F (180°C). Line a muffin pan with 12 paper liners*. Mash the bananas and set them aside.

2. Add the butter and brown sugar for the cupcake batter to a large bowl and mix until light and fluffy. Add the eggs one after another and mix until well combined.

3. Combine flour, baking powder, baking soda, salt, and ground ginger and sift it into the large bowl. Mix in, then add the mashed bananas, sour cream (or yogurt) and milk – mix until just combined. Do not overmix.

4. Divide the batter evenly between the paper liners and bake the cupcakes for about 15-18 minutes, or until a toothpick inserted into the centers of the cupcakes comes out clean. Take the cupcakes out of the oven and let them cool down completely on a wire rack before decorating.

5. For the buttercream, add the egg whites, sugar, and salt to a large bowl and place that on top of a saucepan with simmering water – the water should not touch the bowl. Whisk the egg whites until the sugar has dissolved, and the mixture has reached a temperature of 71°C (160°F). Transfer to the bowl of a stand mixer and mix on high for about 5 minutes until stiff peaks form and the meringue has cooled down to room temperature.

6. As soon as the meringue has the right temperature, gradually add the butter in small pieces and mix in. Next, add the vanilla extract and confectioners‘ sugar. Continue mixing for another 5 minutes or so until the buttercream is very creamy, and all ingredients are well combined. Fill the cream into a piping bag with a star tip and decorate the cupcakes to your liking. Drizzle with melted chocolate, sprinkle with chopped nuts or add a banana slice on top. Be warned, the banana will get brown quite quickly, so add those only when serving immediately.