Prep the pan and oven: Heat the oven to 350°F (175°C). Grease a 9x5-inch loaf pan and line it with a parchment sling for easy removal.

Mash the bananas: In a large bowl, mash the bananas with a fork until mostly smooth with a few small lumps. You should have about 1 1/2 cups.

Add the wet ingredients: Whisk in the granulated sugar, brown sugar, melted butter, oil, eggs, buttermilk (or yogurt), and vanilla until combined and glossy.

Combine the dry ingredients: Sprinkle the flour, baking soda, baking powder, and salt over the wet mixture. Gently fold with a spatula until just combined. A few streaks of flour are okay.

Fold in mix-ins (optional): Add chocolate chips or nuts and fold lightly. Do not overmix—the batter should be thick and slightly lumpy.

Fill the pan: Scrape the batter into the prepared pan. For a pretty top, sprinkle with turbinado sugar or lay a halved banana (cut side up) on the surface.

Bake: Bake for 55–70 minutes, depending on your oven. Start checking at 55 minutes. The bread is done when a toothpick inserted in the center comes out with a few moist crumbs but no wet batter, and the top is deep golden brown.

Cool properly: Let the loaf cool in the pan for 10–15 minutes, then lift it out and cool on a rack for at least 1 hour before slicing. This sets the texture and keeps it from crumbling.

Slice and enjoy: Use a serrated knife for clean slices. Serve warm or at room temperature with butter, nut butter, or a drizzle of honey.