Brownies Nutella yang keterlaluan

Bahan-bahan (16 porsi)

• 400 g / 13 oz Nutella ((Note 1))
• 200 g / 1 3/4 US sticks (14 tbsp) unsalted butter
• 200 g / 1 1/4 cups / 7 oz dark chocolate melts / semi sweet chocolate chips ((Note 2))
• 1 cup (175g) brown sugar (, loosely packed )
• 3 eggs (, room temp)
• 1 tsp vanilla extract
• 1/2 cup (75g) flour (, plain/all purpose, sifted if lump)
• 1/4 cup (30g) cocoa powder (, sifted)
• Pinch of salt