Preheat & Prepare the Loaf Pan: Preheat the oven to 350°F (175°C). Grease a 9×5-inch loaf pan or line it with parchment paper for easy removal.

Mash the Bananas & Mix Wet Ingredients: In a large mixing bowl, mash the ripe bananas with a fork until smooth. Stir in the granulated sugar, brown sugar, melted butter, eggs, and vanilla extract. Mix until well combined.

Add the Dry Ingredients: Add the flour, baking soda, salt, and cinnamon to the banana mixture. Pour in the milk and stir gently until the batter is smooth. Be careful not to overmix.

Make the Cinnamon Swirl: In a small bowl, mix the ¼ cup granulated sugar with 1 ½ teaspoons cinnamon.

Layer the Batter & Cinnamon Swirl: Pour half of the banana batter into the prepared loaf pan. Sprinkle half of the cinnamon sugar mixture evenly over the batter. Pour the remaining banana batter on top, then sprinkle the rest of the cinnamon sugar over it. Use a butter knife or toothpick to gently swirl the cinnamon into the batter, creating a marbled effect.

Add the Topping (Optional): For extra cinnamon flavor, mix 1 tablespoon brown sugar with ½ teaspoon cinnamon and sprinkle it over the top of the loaf before baking.

Bake the Banana Bread: Bake for 50-55 minutes, or until a toothpick inserted into the center comes out clean. If the top browns too quickly, loosely cover the loaf with foil after 30 minutes.

Cool & Serve: Let the banana bread cool in the pan for 10 minutes, then transfer to a wire rack to cool completely. Slice and enjoy warm or at room temperature!