Preheat your oven to 350°F (175°C) and line a loaf pan with parchment paper.

In a large mixing bowl, combine melted butter, brown sugar, and granulated sugar. Add eggs and vanilla extract; whisk until blended. Fold in mashed ripe bananas.

In a separate bowl, whisk together all-purpose flour, salt, and baking soda. Fold dry mixture into wet banana mixture, stirring until just combined.

Pour half of the batter into your prepared loaf pan. Warm Nutella in the microwave for 20-25 seconds, dollop half over the batter and swirl with a knife.

Layer the remaining batter over the Nutella and repeat by dolloping remaining Nutella on top and swirling again.

Bake for 50-55 minutes until the top is golden brown and a toothpick comes out with moist crumbs.

Let the bread cool in the pan for 15 minutes, then transfer to a wire rack to cool completely.