Nutella Brownies are perfectly thick, chewy, fudgy, and slightly gooey with a hint of chocolate hazelnut goodness. One of the best brownies I've ever had!
Preheat the oven to 350°F. Line an 8x8-inch *metal* baking pan with foil or parchment, leaving an overhang, and spray with nonstick cooking spray.
Pour the batter into the prepared baking pan. Bake until a tester comes out with moist crumbs still attached, 35 to 40. Do not overbake, you want to error on the side of underbaking. Let cool to room temperature. Serve at room temperature, warmed, or chilled.
The Nutella flavor is slightly muted with baking. To punch it up, feel free to add a tablespoon of Frangelico to the batter or a cup of toasted chopped hazelnuts if you want a bit of crunch.