Preheat the oven to 350 degrees.

Place the eggs in a large bowl and whisk until foamy. Add in the sugars and keep beating until smooth.

In a small saucepan combine the butter, unsweetened baking chocolate, and chocolate chips. Heat over medium heat, stirring often, until melted and smooth. Remove from heat.

Add the chocolate to the egg mixture and stir until incorporated. Mix in the vanilla.

In a small bowl combine the hazelnut flour, salt, and baking powder. Add the dry ingredients to the wet and stir until combined.

Pour the batter into a 7 x 11 or 9 x 9 pan sprayed with cooking spray. Baking for 30-35 minutes or until a toothpick inserted into the center comes out clean.

Place on a wire rack and cool for at least 30 minutes. Cut into squares and enjoy.