Preheat oven to 180˚C.
Place Dr. Oetker Nona Brownies Original, vegetable oil, water and eggs in a mixing bowl, stir until well combined (with wooden spatula or hand whisk).
Melt cooking chocolate with microwave or by "double boil". Fold melted cooking chocolate into brownie batter.
Pour batter in a greased rectangle baking tray. Bake at 180˚C for 40 minutes.
Set brownies aside to cool completely before cutting into squares.