Preheat your oven to 350°F (175°C) and grease your loaf pan or line it with parchment paper for easy removal.
In a large mixing bowl, combine the granulated sugar, vegetable oil, and peanut butter. Use a whisk to blend them until smooth. Add the overripe bananas and mash them into the mixture until well incorporated. Then, mix in the eggs, milk, vinegar (or lemon juice), vanilla extract, and maple extract.
In another bowl, whisk together the flour, baking soda, and salt (if using). Make sure there are no lumps.
Gradually add the dry mixture to the wet mixture. Use a spatula to gently fold the ingredients together until just combined. Be careful not to overmix; it’s okay if there are a few flour streaks.
Pour the batter into your prepared loaf pan. Smooth the top with a spatula, and tap it lightly on the counter to remove any air bubbles.
Bake in the preheated oven for 50-60 minutes, or until a toothpick inserted into the center comes out clean. If the top starts to brown too quickly, cover it loosely with aluminum foil.
Once baked, remove the bread from the oven and let it cool in the pan for about 10 minutes. Then, transfer it to a wire rack to cool completely.
In a small bowl, whisk together the powdered sugar, melted butter, and heavy whipping cream until smooth. Drizzle it over the cooled banana bread.
