Preheat the Oven and Prepare the Pan: Preheat your oven to 350°F (175°C). Grease a 9x5-inch loaf pan with butter or non-stick cooking spray, or line it with parchment paper for easier removal.

Mash the Bananas: In a large mixing bowl, mash the bananas with a fork or potato masher until smooth but with a few small chunks remaining.

Combine Wet Ingredients: Add the melted butter, brown sugar, white sugar, and vanilla extract to the bananas. Whisk until well combined. Add the eggs one at a time, beating well after each addition to create a smooth mixture.

Add Greek Yogurt (or Sour Cream): Stir in the Greek yogurt or sour cream, which will add extra moisture and tenderness to the banana bread.

Mix Dry Ingredients: In a separate bowl, whisk together the all-purpose flour, baking soda, salt, and ground cinnamon.

Combine Wet and Dry Ingredients: Gradually fold the dry ingredients into the wet mixture, stirring until just combined. Avoid over-mixing, as this can make the banana bread dense.

Add Optional Mix-ins: Gently fold in any desired mix-ins, like chopped walnuts, chocolate chips, or pecans, for extra flavor and texture.

Bake the Bread: Pour the batter into the prepared loaf pan, spreading it evenly. Bake for 60-70 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs. Check the bread around the 50-minute mark and cover with aluminum foil if it’s browning too quickly.

Cool and Serve: Allow the banana bread to cool in the pan for 10 minutes, then transfer it to a wire rack to cool completely. Slice and enjoy!