Preheat oven to 360°F and grease a 9 x 5 inch baking tin.
In a medium mixing bowl, whisk together the all purpose flour, baking soda, and salt. Set aside
Mash the bananas in a medium bowl until they have broken apart. Small chunks of banana are okay. Mix in the brown sugar
Mix in the vanilla extract. Add the eggs one at a time, mixing in between each addition until well-incorporated
Add the Greek yogurt and mix until well-incorporated
Add the dry ingredients, mixing until just incorporated. Be careful not to over-mix, as this can cause your bread to be tough. Slowly pour in the oil and mix well. The mixture will look a little chunky at first, but will smooth out after a minute or two.
Fold in the roasted hazelnuts and pour into the prepared baking tin
Top with spoonfuls of hazelnut chocolate spread, and swirl in with a knife
Place in the middle rack of the oven and bake for 60 - 65 min until a toothpick or knife comes out clean. A few moist crumbs are okayIf you find the loaf browning too quickly around the 30 - 40 minute mark, you can tent with aluminum foil Remove from oven and let cool for 10 – 15 minutes.