How to make
Preheat the oven to 320°F (160 °C). Melt the butter, sugar, cocoa and salt in a water bath, while stirring.
Let them cool slightly, then add the eggs, flour and nuts. Vigorously beat to homogeneity and pour it into an oven dish, which you've covered with aluminum foil or baking paper.
Bake for about 25-30 minutes, until fully cooked, then cool it completely. Cut it into 16 or 25 squares. Your baking tray needs to be 8″ (20 cm) x 8″ (20 cm).