Preheat your oven to 350°F (175°C). Grease and flour your loaf pan or line it with parchment paper.
In a mixing bowl, mash the ripe bananas until smooth. You should have about 1.5 cups of mashed banana.
Add the peanut butter, granulated sugar, brown sugar, eggs, and vanilla extract to the mashed bananas. Mix well until fully combined.
In a separate bowl, whisk together the flour, baking soda, baking powder, and salt.
Gradually add the dry ingredients into the wet mixture, stirring gently until just combined. If desired, fold in the chopped peanuts.
Pour the batter into the prepared loaf pan, smoothing the top with a spatula.
Bake in the preheated oven for 60 minutes or until a toothpick inserted in the center comes out clean.
Remove the banana bread from the oven and let it cool in the pan for about 10 minutes before transferring it to a wire rack to cool completely.
For an added twist, consider mixing in chocolate chips or dried fruit if desired.
Store the banana bread wrapped in plastic wrap at room temperature for up to 3 days or freeze for up to 3 months.