Preheat oven to 350 degrees F. Grease & flour a 9×5 loaf pan.
Combine flour, cocoa powder, baking soda and baking powder in a large bowl. Set aside.
Cream butter and sugars together until fluffy. Stir in eggs and bananas. Add banana mixture and chocolate chips to flour mixture. Stir just until combined.
Bake 50-60 minutes, or until a toothpick comes out clean.
Heat half & half and brown sugar over medium heat until brown sugar has dissolved and tiny bubbles start to form on the edges. Stir in vanilla and butter until melted and turn off heat. Add chocolate chips and do not stir, let sit 2-3 minutes.
Whisk chocolate chips until smooth. Cool completely and drizzle over bread.