Preheat your oven to 350°F (175°C) and grease two 8.5 x 4.5-inch loaf pans generously with butter.

In a stand mixer, beat together 1 cup of softened unsalted butter and 1 cup of granulated sugar until light and fluffy, about 3-5 minutes.

Add 4 large eggs, 2 cups of mashed ripe bananas, and 1/2 cup of buttermilk to the mixture and mix on low until combined.

In a separate bowl, whisk together 2 cups of all-purpose flour, 1 teaspoon of baking soda, and 1/2 teaspoon of salt, then gradually add to the wet mixture.

Pour the batter evenly into the prepared loaf pans and smooth the tops. Bake for 60-70 minutes or until golden brown and a toothpick comes out clean.

Let the loaves cool in the pans for about 10 minutes, then transfer to a wire rack to cool completely.