Preheat oven to 170 degrees celcius. Grease and line a 9X5- inch loaf tin.
Mash the bananas with a fork. In a large mixing bowl, whisk together sugar and eggs until well incorporated. Whisk in the mashed bananas, buttermilk and vanilla extract.
Warm 100 grams in the microwave for 20 seconds and mix into to the egg mixture.
Sift the flour, salt, baking powder and baking of soda into the egg mixture then mix until combined.
Mix in the melted butter.
Pour the batter into the prepared loaf tin, then pour over remaining biscoff. Use a knife to swirl the spread. Top the batter with biscoff cookie pieces.
Bake for 50-60 minutes or until a toothpick or skewer inserted in the centre comes out clean. 30 minutes into baking, loosely cover the bread with foil to help prevent the top and sides from getting too brown. Leave tin to cool for 15 minutes, then invert onto cooling rack.