For the Brownies

1. Preheat the oven to 350F. Lightly grease and line an 9×9 pan with parchment paper.
2. In a medium saucepan over medium heat, melt the butter. Add chocolate and whisk until fully melted. You can do this using a double broiler if you prefer.
3. In a large bowl, whisk together the sugar, brown sugar, eggs + yolk, vanilla extract and salt.
4. Whisk in the chocolate mixture until fully incorporated. Fold in the flour, hazelnuts and chocolate chips.
5. Transfer batter to prepared pan, and cook for 30-35 minutes, or until toothpick inserted into center comes out with moist crumbs attached.
6. Allow to cool completely before adding the ganache on top.

For the ganache

1. In a medium pot, simmer heavy cream over medium heat. Don’t let it come to a boil!
2. Remove from heat and add chopped chocolate and chocolate chips.
3. Let stand for 1 minute, then whisk until chocolate melts.
4. Pour over cooled brownies and let cool at room temperature for at least for hours.