1. Preheat the oven to 350°F (180°C). Grease a loaf pan* (about 9.5×5 inches) lightly and line it with a piece of baking parchment. Set aside. Mash the two bananas, chop the chocolate and walnuts coarsely, and set them aside.

2. Add the butter and both sugars to a large bowl and mix until light and fluffy. Add the eggs one at a time and mix well after each addition. Next, add the buttermilk and vanilla extract and stir in. Mix the spelt flour with baking powder, baking soda, and salt in a separate bowl then add to the large bowl and mix until just combined. Add the mashed bananas, chopped chocolate, and walnuts and fold in. Pour the batter into the prepared loaf pan and smooth out the top. Cut the banana for the decoration in half lengthways and place on top of the batter. Bake the banana bread for about 60-70 minutes or until a wooden skewer inserted into the center of the cake comes out clean.

3. Let the banana bread cool down for about 10-15 minutes inside the loaf pan, then remove and let cool down completely on a wire rack.