Mash bananas using a fork or food processor. Overripe bananas are easy to mash. If you use food processor, pour some milk to make it easier.  

Melt unsalted butter in a microwave or on a pan with low heat. Do not let it boil. Set aside.

In a bowl, put in eggs, palm sugar, white sugar, and salt. Mix with high speed for 10 minutes.

The batter should be thick and pale and leave trail after 10 minutes.

Put in the mashed bananas. Mix for a while.

Sieve flour, baking powder, baking soda, and cinnamon ground into the batter.

Mix and fold the batter using a spatula.

Pour in melted butter and coconut oil. Put in vanilla extract.

Mix and fold.

Pour the well-mixed batter in a baking pan or muffin cup.

Knock the pan a few times to let the air out.

Put the pan in a pre-heated oven of 180°C for 5 minutes. Take it out when it has a little bit of skin on top. Decorate with some bananas.

Put back into the oven and let it bake for 40 minutes. Insert a bamboo stick to check the cake.

Take out from the oven and let it cool on the cooling rack.

Cut the banana bread in slices. Enjoy!