Preheat oven at 350°F. Prepare a loaf pan with non stick spray, set aside.
Mash bananas in the bottom of a large bowl. Whisk in melted butter, then brown sugar, egg, and vanilla. Place baking soda, salt, cardamom, flour and cocoa powder in a sifter. Sift over wet ingredients. Stir dry and wet ingredients with a spoon until just combined. Stir in chocolate chips.
Pour into prepared pan and bake 55 to 60 minutes. Let cool in pan for 10 minutes before removing. Personally, I like this best straight out of the oven, but will still be delicious for up to 2 days.
Recipe by the modern barista at https://themodernbarista.com/index.php/2016/02/22/sumatra-aceh-with-double-chocolate-banana-bread/