Mix lukewarm water, buttermilk, yeast, salt, sugar, butter and banana puree in a large bowl.
Whisk the mixture and gradually add it to the flour and mix it using a wooden spatula until the flour is well mixed.
Close the bowl and allow the dough to rise up to two hours in a warm place.
Once the dough is ready, refrigerate it for half an hour, it will be easier to handle the dough.
Take the dough , dust lightly with flour and roll the dough into a medium sized loaf, arrange this rolled loaf in a greased loaf pan, cover the dough with a wet towel, allow the dough to rise for an hour again. Bake the bread at 350F for 30-35 minutes until the crust turns brown.