These chocolate hazelnut blondies have all the best textures - crunchy, cakey, and fudgy. Chopped hazelnuts and a swirl of chocolate hazelnut butter level up these blondies into a league of their own.
Preheat the oven to 350°F. Grease an 8-inch x 8-inch baking dish with butter or cooking spray.
In a large mixing bowl, whisk together the vegetable oil, eggs and vanilla.
Add the brown sugar, flour, baking powder and salt. Mix just until there is no visible dry flour.
Fold in the chocolate chips and chopped hazelnuts.
Spread the blondie mixture evenly into the greased baking dish. Dollop spoonful's of the chocolate hazelnut butter on top, then use a toothpick or a knife to swirl it around.
Bake for 30 to 45 minutes, until a toothpick inserted into the center comes out clean. Let cool for at least 20 minutes, then slice and enjoy!