Preheat oven to 180 degrees Celsius.
Line a square 7 inch x 7 inch pan with parchment paper.
Mix everything except for the chocolates and walnuts in a bowl and stir until everything is blended in.
If you want your brownie to be softer and more cakey, add one more egg, and beat more.
Add the walnuts and chocolates.
Spread the batter into the prepared pan.
Even out the surface and add toppings. Do not press them in.
Bake on a medium shelf in the oven for 30 minutes.
Cut them into squares or rectangles and serve.