Pre-heat your oven to 170°C/ 338°F (fan assisted).
In a saucepan on medium-high heat, add the butter and brown for around 5 minutes, until browned.
Grease a rectangular baking tin (23x12 cm) with a small amount of butter and place a strip of baking paper in the centre.
Smash the bananas up with a fork, forming a paste. Add the browned butter and egg. Whisk. Add the sugars, whisk. Finally add the flour, baking powder, salt + soda to the bowl, whisk until combined.
Add your chopped chocolate (leaving a handful aside for the top) and combine with a wooden spoon. Spoon your banana bread mixture into the loaf tin.
Cover with either tin foil or baking paper. Bake the banana bread for around 50 minutes, or until a fork comes out of the middle clean. I took the baking paper cover off after about 40 minutes. Leave to cool completely in the loaf tin. I put the frosting on the next day so simply covered the tin with cling film once it was cool and left on the side at room temp. When ready to eat: in a bowl, whisk cream cheese, vanilla and icing sugar. Taste and add more icing sugar if you want it sweeter!
In a saucepan, add butter and cinnamon powder, melt and mix together. Remove the banana bread from the tin, add the frosting and puddles of the cinnamon butter on top. Swirl the butter, slice and enjoy!