1. Preheat the oven to 170°C and line a 33 x 23 x 5cm baking tray with greaseproof paper.
2. On a double boiler melt the chocolate and butter together until smooth. Let it cool slightly.
3. Transfer the melted chocolate, along with sugar and eggs to the blender. Put the lid on and blend for 30 second setting.
4. Add the flour and pulse 3-4 times. Use the tamper tool to make sure it’s all well incorporated.
5. Scrape the batter out of the jar and into the prepared pan. Bake for 35 minutes, or until a toothpick comes out clean.
6. Serve warm with Vanilla Ice Cream.