3/4 cup granulated sugar (or 1/2 cup granulated + 1/4 cup brown sugar)
1 large egg, beaten
1 teaspoon vanilla extract
1 1/2 cups all-purpose flour
1 teaspoon baking powder
1/2 teaspoon baking soda
1/4 teaspoon salt
1 teaspoon ground cinnamon (for swirl)
2 tablespoons granulated sugar (for swirl)
Optional: 1/2 cup chopped walnuts or pecans
Instructions
Preheat the oven to 350°F (175°C). Grease a 9×5-inch loaf pan and line with parchment if you like easy release.
In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.
In a larger bowl, whisk the melted butter with sugar until it’s smooth and glossy. Beat in the egg and vanilla until well combined.
Stir in the mashed bananas until the mixture looks uniform and a little shiny from the banana moisture.
Fold the dry ingredients into the wet ingredients just until combined. The batter should be thick but damp; overmixing makes the loaf dense.
Prepare the cinnamon swirl by mixing the 1 teaspoon cinnamon with 2 tablespoons sugar in a small bowl.
Spread half of the batter into the prepared loaf pan. Sprinkle half of the cinnamon-sugar swirl over the batter. Top with the remaining batter and swirl gently with a knife to create ribboned pockets of cinnamon.
Bake for 60–65 minutes, until the top is golden and a toothpick inserted into the center comes out with a few moist crumbs. If the top browns too quickly, tent with foil for the last 10 minutes.
Let the bread rest in the pan for 10–15 minutes, then transfer to a wire rack to cool completely before slicing.
