In the bowl of an electric mixer, combine the sugar and butter beating at medium speed until fluffy. On low-speed, add the banana, milk, greek yogurt and eggs- mixing until combined.
In a small bowl, whisk together the flour, cocoa powder, instant espresso powder, baking soda and salt.
Keeping the mixer on low-speed and slowly add the dry ingredients to the wet ingredients. Beat just until blended.
Scrape the batter into a 9×5 inch metal loaf pan coated with cooking spray and bake at 350 degrees for 1 hour or until a toothpick inserted into the center comes out clean.
Cool in pan for 10 minutes on a wire rack. Remove from pan and cool on rack.
MAKE THE TOPPING:
Add the chocolate chips and cream to a small saucepan over medium heat. Cook the chocolate until smooth, stirring constantly. Remove from the heat.
Immediately spoon the ganache over the banana bread and allow to cool before serving.