Prep the pan and oven. Heat the oven to 350°F (175°C). Grease a 9x5-inch loaf pan and line it with a parchment sling for easy removal.

Mash the bananas. In a large bowl, mash the ripe bananas until mostly smooth with a few small lumps. You should have about 1 1/4 cups.

Whisk in the wet ingredients. Add peanut butter, melted butter, eggs, brown sugar, and vanilla. Whisk until the mixture looks smooth and glossy.

Combine the dry ingredients. In a separate bowl, whisk together flour, baking soda, baking powder, salt, and cinnamon.

Bring the batter together. Add the dry mixture to the wet mixture. Stir gently with a spatula until just combined. Do not overmix; a few streaks of flour are fine.

Fold in the chocolate. Stir in 3/4 to 1 cup chocolate chips (and nuts if using) until evenly distributed. The batter will be thick.

Fill the pan. Scrape the batter into the prepared pan. Smooth the top and sprinkle a handful of chocolate chips over the surface for a bakery-style look.

Bake. Bake for 55–65 minutes, or until a toothpick inserted in the center comes out mostly clean with a few moist crumbs. Tent loosely with foil at the 45-minute mark if the top browns too quickly.

Cool. Let the loaf cool in the pan for 10–15 minutes, then lift it out and transfer to a wire rack. Cool for at least 45 minutes before slicing to set the crumb.

Serve. Slice thick or thin. Enjoy warm, at room temp, or lightly toasted with a swipe of butter or extra peanut butter.