Preheat your oven to 350°F (175°C). Grease a loaf pan with butter or cooking spray.

Mash three ripe bananas in a large mixing bowl until smooth.

Cream together ½ cup of unsalted butter with ½ cup granulated sugar and ½ cup brown sugar until fluffy.

Incorporate two room temperature eggs and 1 teaspoon of vanilla extract into the creamed mixture.

Sift together 1 ½ cups of all-purpose flour, 1 teaspoon of baking soda, ½ teaspoon of salt, and 1 teaspoon of ground cinnamon in another bowl.

Combine the dry ingredients into the wet mixture gradually, folding gently until just combined.

Prepare the cinnamon sugar swirl by mixing ¼ cup of granulated sugar with 1 tablespoon of ground cinnamon.

Layer half of the batter into the prepared loaf pan, then sprinkle half of the cinnamon sugar mixture on top.

Add the remaining batter and finish with the last of the cinnamon sugar mixture.

Bake for 60-70 minutes or until a toothpick inserted in the center comes out clean.

Cool the bread in the pan for about 10 minutes before transferring it to a wire rack.