Preheat your oven to 350°F (175°C). Grease a 9x5-inch loaf pan or line it with parchment paper.
In a large mixing bowl, combine the mashed bananas and peanut butter until smooth.
Stir in the melted coconut oil, brown sugar, egg, and vanilla extract until well combined.
Add the baking soda and salt, mixing until incorporated.
Gradually fold in the flour until just combined. Be careful not to overmix. If using, gently fold in the chocolate chips.
Pour the batter into the prepared loaf pan and smooth the top.
Bake for 50-60 minutes, or until a toothpick inserted into the center comes out clean.
Allow the bread to cool in the pan for about 10 minutes before transferring it to a wire rack to cool completely.