Steps
1. Preheat your oven to 180°C (350°F).
2. In a small bowl, melt the dark chocolate and butter together in the microwave in 20-second intervals until smooth.
3. In another bowl, whisk the egg and sugar until frothy.
4. Combine the melted chocolate mixture with the egg mixture, stirring well.
5. Sift in the flour, cacao powder, and salt, folding gently until fully incorporated.
6. Pour the batter into a small greased ramekin.
7. Bake for 12-15 minutes, or until the edges are set but the center is still slightly gooey.
8. Let it cool for a couple of minutes before serving, optionally dust with cacao powder.