Preheat your oven to 350°F (175°C) and grease your loaf pan with butter or line it with parchment paper.

In a large mixing bowl, peel and mash your ripe bananas until smooth, about 2–3 minutes.

In a separate bowl, cream together softened butter and granulated sugar until light and fluffy, then mix in the eggs.

Whisk together flour, baking soda, salt, and ground cinnamon, then fold into the wet mixture until just combined.

Pour half of the batter into the loaf pan, sprinkle the cinnamon sugar mixture over it, then top with the remaining batter.

Bake for 50–60 minutes, until a toothpick comes out clean. The bread should be golden brown.

Let the bread cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.