Who needs plain old banana bread when you can have banana bread with Nutella in it?
Preheat the oven to 350°F. Coat the inside of a 4x8-inch loaf pan with cooking spray.
In a large mixing bowl, mash the bananas with a fork until smooth. Then stir the melted butter into the mashed bananas. Mix in the baking soda, salt, sugar, egg, and vanilla.
Add the flour and gently stir until it's well combined. (Don't over mix or your banana bread will be too dense.)
In a microwave safe bowl, microwave the Nutella on high power for 30 seconds. Give it a good stir. Then add about 1/2 cup of the banana bread batter into the softened Nutella and stir to combine.
Add the banana bread batter into your loaf pan, alternating spoonfuls of the Nutella mixture spread throughout. Drag a knife through the pan a few times to create swirls. Then bake for 50-55 minutes at 350°F.
After letting the banana bread cool for a few minutes in the pan, remove the banana bread from the pan and let cool completely on a wire rack before slicing and serving.