METHOD

Preheat the oven to 180°C/350°F.
Melt 150 g of chocolate with the butter.
Whisk the eggs with the salt and sugar for 4 to 6 minutes.
Mix the chocolate with the eggs. Sift the cocoa powder into the mixture and mix well. Add the chopped chocolate and stir until incorporated.
Refrigerate for 6-8 minutes. Pour onto a parchment-lined cookie sheet and bake for 8-9 minutes. Let cool before removing from cookie sheet