Rich, fudgy chocolate brownies swirled with Nutella and studded with toasted hazelnuts. Quick to make with simple ingredients, no mixer required, and perfect for a decadent everyday treat.
Prepare Your Baking Pan: Begin by preheating your oven to 350°F (175°C). While the oven warms, prepare an 8-inch square baking pan by lightly spraying it with cooking spray, or you can line it with parchment paper for easier removal. Make sure every corner and edge is coated to prevent sticking. Set the pan aside on a flat surface while you prepare the brownie batter.
Melt Butter and Chocolate: Place the unsalted butter and finely chopped unsweetened chocolate in a medium microwave-safe bowl. Heat the mixture in 30-second intervals, stirring thoroughly after each interval. Continue until the chocolate is fully melted and smooth, with no lumps. Take care not to overheat, as chocolate can seize. Allow this mixture to cool slightly for about 5 minutes, so it doesn’t cook the eggs in the next step.
Mix Eggs and Sugar: In the slightly cooled chocolate-butter mixture, add the two large eggs one at a time, stirring well after each addition. Then add the granulated sugar and mix thoroughly until the mixture is smooth and glossy. This step ensures the brownies will have a tender, moist texture and helps incorporate air for a light yet fudgy consistency.
Add Vanilla and Leavening: Stir in the teaspoon of vanilla extract along with the 1/4 teaspoon of baking soda and 1/4 teaspoon salt. Mix gently but thoroughly until all ingredients are fully combined. This step ensures your brownies have a well-rounded flavor and a balanced rise during baking.
Incorporate the Flour: Gradually fold in the 2/3 cup of all-purpose flour using a spatula or spoon. Mix only until the streaks of flour disappear, being careful not to overmix. Overmixing can make the brownies dense and dry, so aim for a just-combined, silky batter.
Fold in Hazelnuts: Add the 3/4 cup of chopped toasted hazelnuts to the batter and fold gently until evenly distributed. Toasting the hazelnuts beforehand enhances their nutty flavor and adds a subtle crunch that perfectly contrasts with the fudgy chocolate.
Pour Batter Into Pan: Transfer the prepared batter into your greased or parchment-lined 8-inch baking pan. Use a spatula to smooth the top evenly, ensuring it’s level for uniform baking. The even surface helps the Nutella swirl stand out beautifully and allows the brownies to bake consistently.
Add Nutella Swirl: Dollop spoonfuls of 1/2 cup Nutella over the top of the brownie batter. Using a butter knife or skewer, gently swirl the Nutella into the batter in a marbled pattern. Avoid overmixing—light, loose swirls create a visually appealing pattern and pockets of rich, gooey chocolate in each bite.
Bake Brownies: Place the pan in the preheated oven and bake for 25–30 minutes. The top should appear set, slightly shiny, and firm to the touch, while the center remains fudgy. A toothpick inserted in the center may come out with a few moist crumbs, which is perfect for a gooey brownie. Avoid overbaking to maintain a soft, decadent texture.
Cool Completely: Remove the pan from the oven and place it on a wire rack. Allow the brownies to cool completely before slicing. Cooling ensures the Nutella swirl sets slightly and the brownies hold their shape, making them easier to cut into neat squares.
Serve and Enjoy: Once cooled, cut the brownies into 9 equal squares using a sharp knife. Serve them as a standalone dessert, with a scoop of ice cream, or a drizzle of chocolate sauce. These brownies are perfect for everyday indulgence or special occasions, offering a rich chocolate-hazelnut experience in every bite.
Notes
If you only have salted butter, simply omit the additional salt. This will slightly enhance the sweet-salty balance, giving your brownies a subtle savory kick.
Unsweetened chocolate provides the richest, most decadent flavor, but you can substitute dark or semi-sweet chocolate if needed. The flavor will be slightly milder but still delicious.
Nutella swirls are optional, but they add gooey pockets of chocolate-hazelnut flavor and a beautiful marbled effect.
Toasting hazelnuts before adding them enhances their natural nutty aroma and crunch.
Be careful not to overmix the batter after adding flour—overmixing can make brownies dense rather than fudgy.