Preheat your oven to 350°F (175°C). Grease your 9x13 inch baking pan with cooking spray or line it with parchment paper for easier removal.
In a large mixing bowl, combine the Duncan Hines Chewy Fudge Brownie Mix, eggs, water, and vegetable oil. Stir until well mixed and the batter is smooth. Be careful not to overmix.
Chop 8 Ferrero Rocher chocolates into quarters and fold them into the brownie batter.
Pour the brownie batter into the prepared baking pan, ensuring it is evenly spread out.
Bake the brownies in the preheated oven for 25-30 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.
After baking, remove the brownies from the oven and immediately place the remaining Ferrero Rocher chocolates on top, pressing them gently into the surface.
Allow the brownies to cool in the pan on a cooling rack for about 10-15 minutes before cutting them into squares.
