Preheat your oven to 350°F (175°C) and grease a 9x5-inch loaf pan.

In a large mixing bowl, mash 2-3 ripe bananas until smooth, then add granulated sugar, brown sugar, melted butter, eggs, and vanilla extract. Whisk until well-combined.

Gently sprinkle in the baking soda and salt, then fold in the all-purpose flour until just combined.

In a small bowl, mix together granulated sugar and cinnamon for the swirl.

Pour half of the banana batter into the prepared loaf pan, then sprinkle half of the cinnamon-sugar mixture over the batter.

Pour the remaining banana batter over the first layer and top with the remaining cinnamon-sugar mixture.

Gently swirl the batters together using a knife or a skewer in a figure-eight motion.

Place the loaf pan in the oven and bake for 50-60 minutes; check for doneness with a toothpick.

Allow the bread to cool in the pan for about 10-15 minutes, then transfer to a wire rack to cool completely.

Combine powdered sugar and milk for the glaze, then drizzle it over the cooled bread.