Preheat the oven to 170 C /338 F. Middle rack.
Butter and dust with flour 1 loaf pan 9″ inch or cut out 2 pieces of parchment paper and place it in the loaf pan.
In a large bowl of standing mixer, beat on medium-high speed brown sugar with butter for a few minutes and then add eggs (one at the time). Make sure eggs are well incorporated.
Add sour cream (or yoghurt), zest from one lemon and mashed bananas. Beat on medium speed, until well incorporated.
In another large bowl, add sifted flour, cocoa powder, baking powder, baking soda, salt, chopped nuts, chocolate chips and mix with spatula.
Slowly incorporate the flour mix into the wet ingredients, while running the mixer on low sped. At the end add chopped canned pears and incorporate them with spatula, not to mush them.
Pour the batter slowly into loaf pan, top with sliced bananas, chips and few chopped walnuts. Heat the peanut butter in the microwave for 15 seconds and drizzle it over the bread.
Bake on the middle rack 170 C /338 F for about 60-65 minutes. Check on the bread in mid time and add aluminum foil on top to prevent burning. At the end insert the toothpick to make sure the bread is done.
Take it out of the oven and let cool down on wired rack for 20 minutes. Cut in slices and serve.