Preheat your oven to 350°F (175°C).

In a large mixing bowl, mash the ripe bananas. Add the creamy peanut butter, granulated sugar, and brown sugar. Mix until well blended.

In a separate bowl, whisk together the baking soda, salt, and all-purpose flour. Set aside.

Add the eggs and vanilla extract to the banana mixture. Stir until fully incorporated. Gradually add the dry ingredients to the wet mixture and mix gently until just combined.

Fold in the grape jelly and chopped walnuts (if using) into the batter.

Pour the batter into a prepared 9x5-inch loaf pan and smooth the top.

Bake for 50-60 minutes, checking for doneness with a toothpick.

Let the bread cool in the pan for about 10 minutes before transferring to a wire rack to cool completely.