Pre-heat the oven to 180C (350F)
Melt the butter. Let it cool for a little.
Mash the bananas in a large bowl,(you will be adding the rest of the ingredients into it). Set aside.
Chop the chocolate,(if using chocolate drops skip this part).
Whisk the eggs till foamy.
In a bowl sift flour, baking soda, and baking powder,(add instant coffee powder if using). Add salt. Mix.
In the bowl with the mashed banans add the sugar, warm melted butter, and whipped eggs. Mix till combined.
To the wet mixture add the flour and fold gently. Don't over mix. After the first few folds add the 100g chopped chocolate, and fold a few more times.
Line a 10" by 4.5"(25x11cm) loaf pan with parchment paper.
Transfer the batter to the pan and top it off with the rest chopped chocolate.
Transfer to the oven and bake for about 50-55min. Time depends on your oven. Check after 45-50min by inserting a toothpick into the center of the loaf, if it comes out clean, it's ready.
Let it cook for few minutes in the pan. After that take it out of the pan into a cooling rack.
You can cut into it while still warm. Enjoy!