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

In a mixing bowl, combine mashed bananas, granulated sugar, brown sugar, melted butter, eggs, and vanilla extract until smooth.

Sprinkle baking soda and salt over the mixture, then gently fold in the all-purpose flour until just incorporated.

In a small bowl, mix together the 1/4 cup sugar with the tablespoon of cinnamon to create the cinnamon sugar mixture.

Pour half of the batter into the loaf pan, sprinkle with half of the cinnamon sugar, then add the remaining batter and top with the rest of the cinnamon sugar.

Use a knife or skewer to gently swirl through the batter to create a marbled effect.

Bake in the preheated oven for 50-60 minutes or until a toothpick inserted in the center comes out clean.

Let the bread cool in the pan for 10-15 minutes before transferring to a wire rack.

For the glaze, mix powdered sugar with milk until smooth and drizzle over cooled banana bread.