In a skillet, add the butter and cook until it browns and smells nutty. Set aside to cool. Preheat the oven to 350°F. And grease, then flour a 9x5 loaf pain.
In a bowl, mash the bananas, then beat in the eggs, yogurt, and sugar. Once the butter is slightly cool, stir in the butter.
In a large bowl, Mix in the salt, flour, and baking soda.
Add the wet ingredients into the flour mixture and add in ¼ cup of the Nutella. Mix well.
Add in half the batter into the loaf pan, then add spoonfuls of the Nutella. Top with the remaining Nutella and add spoonfuls of more of the Nutella.
Bake for 50 - 60 minutes, or until a toothpick comes out clean. Cool completely before removing from the pan.