Ingredients

• 3 ripe bananas, mashed
  
• 1/2 cup unsalted butter, melted
  
• 1 cup granulated sugar
  
• 1 large egg, beaten
  
• 1 teaspoon vanilla extract
  
• 1 1/2 cups all-purpose flour
  
• 1 teaspoon baking soda
  
• 1/2 teaspoon salt
  
• 2 teaspoons ground cinnamon
  
• 1/4 cup brown sugar

Instructions 

1. Preheat the oven to 350°F (175°C). Lightly grease a 9×5-inch loaf pan.
2. Combine the wet ingredients:
   In a large bowl, mix together the mashed bananas, melted butter, granulated sugar, beaten egg, and vanilla until the mixture is smooth.
3. Prepare the dry ingredients:
   In another bowl, whisk the flour, baking soda, and salt. Add this dry mixture to the banana mixture, stirring only until everything is incorporated.
4. Make the cinnamon swirl:
   In a small bowl, stir together the ground cinnamon and brown sugar.
5. Layer the batter:
   Pour half the banana batter into the loaf pan. Sprinkle half of the cinnamon mixture over it. Add the remaining batter, then top with the rest of the cinnamon mixture.
6. Create the swirl:
   Use a knife or skewer to gently drag the cinnamon mixture through the batter for a marbled look. Avoid overmixing so the swirl stays defined.
7. Bake for 60–70 minutes, or until a toothpick inserted into the center comes out clean. If the top browns too quickly, loosely cover the loaf with foil.
8. Cool:
   Let the bread sit in the pan for 10 minutes before moving it to a wire rack to cool completely.