Preheat the oven to 400°F. Spread the hazelnuts onto a baking sheet. Roast the hazelnuts for 5 minutes. While the hazelnuts are still warm, use a towel to rub them in order to peel the skins. Discard the skins. Roughly chop the hazelnuts and set aside.

In a large mixing bowl, whisk the eggs. Add the brown sugar and Nutella, whisking until smooth. Gradually add the milk, whisking until incorporated. Stir in the vanilla and salt. Add the brioche bread cubes and half of the chopped hazelnuts to the egg mixture and mix well until the liquid has been absorbed by the bread (it will absorb very quickly). Grease an oven-safe baking dish with butter (I used 2, 6” wide bowls that are 3” high…a regular 9×13” baking dish will work, too). Add the bread mixture to the dish. Top with the remaining hazelnuts.

Lower the heat of the oven to 350°F. Bake the bread pudding for 40-45 minutes, or until cooked through. Cover the bread pudding with foil after 30 minutes if it is looking too brown on top.

Serve the bread pudding with warm Nutella on the side. Sprinkle powdered sugar over top right before serving.