Preheat your oven to 350°F (175°C). This ensures your bread bakes evenly.
Grease your 9x5 inch loaf pan with non-stick spray or line with parchment paper for easy removal.
In a large mixing bowl, combine the melted butter, granulated sugar, and light brown sugar. Whisk until smooth. Add the eggs, sour cream (or Greek yogurt), and vanilla extract. Mix well until fully combined.
Mash the ripe bananas in a separate bowl, then fold them into the wet mixture. Ensure the bananas are well incorporated.
In another bowl, whisk together the flour, baking soda, cinnamon, and salt. Gradually add the dry ingredients to the wet mixture, stirring gently until just combined. Be careful not to overmix!
Fold in the box of vanilla instant pudding mix to enhance the moisture and flavor of the bread.
Pour the batter into the prepared loaf pan. Bake for 60-70 minutes, or until a toothpick inserted into the center comes out clean.
Once baked, remove the bread from the oven and allow it to cool in the pan for about 10 minutes. Then, transfer it to a wire rack to cool completely. Slice and enjoy your delicious Six-Banana Banana Bread!