.
Preheat the oven to 180°C (356°F).
Melt the chocolate and butter together using a double boiler.
Add sugar and mix well.
Add the eggs one at a time, stirring after each addition.
Sift in flour and salt, then mix until combined.
Pour the batter into a pan lined with parchment paper.
Bake in the preheated oven for 20–25 minutes.
Let cool completely, then cut into pieces to serve.