Preheat your oven to 350°F (175°C). Grease your 9x5 inch loaf pan with butter or non-stick spray, or line it with parchment paper for easy removal.
In a large mixing bowl, use an electric mixer or whisk to cream together the softened butter and granulated sugar until the mixture is light and fluffy. This step is key to a tender crumb.
Beat in the eggs one at a time, mixing well after each addition. The eggs help bind the ingredients and give the bread structure.
Stir in the mashed bananas, buttermilk, and vanilla extract until everything is well combined. The bananas should be very ripe for maximum flavor and moisture.
In a separate bowl, whisk together the all-purpose flour, baking soda, and salt. This ensures your leavening and salt are evenly distributed.
Gradually add the dry ingredients to the wet mixture, folding gently with a spatula until just combined. Avoid overmixing to keep your bread light and tender.
If you want some extra texture and flavor, fold in your choice of chopped nuts or semi-sweet chocolate chips now.
Pour the batter into your prepared loaf pan and smooth the top. Bake in the preheated oven for 60-70 minutes, or until a toothpick inserted into the center comes out clean.
Allow the banana bread to cool in the pan for about 15 minutes before transferring it to a wire rack to cool completely. Slice and savor with your favorite spread or simply on its own.